Physics A
If you wish to calculate the area of a small rug, and the length and width are reported as 1 yard by 2 feet, what must first be done in order to find the area?
Either change feet to yards or yards to feet, so that both measurements are in the same units.
Two horses are side by side on a carousel. Which has a greater tangential speed-the one closer to the center or the one farther from the center?
The horse closer to the center has a greater tangential speed.
A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the collision, which of the following is true of the first ball?
It comes to rest.
If a 1 mole of a gas occupied 22.4 liters volume at 298 K, what would happen to its volume if the temperature was raised by 30 K and the pressure was kept constant?
It would expand by about 10%.
Is there an outward force in circular motion?
No, the outward tendency is not a force.
The moon is about 250,000 miles from Earth. If the moon were to recede to 750,000 miles from Earth, what would be the effect on the tides on Earth, which are caused by the moon's gravitational pull?
They would be 1/9 as strong.
Which would hit the ground first if dropped from the same height in a vacuum-a feather or a metal bolt?
They would hit the ground at the same time.
If right is defined as positive displacement, the total displacement of an object lying to the right of the frame of reference is always positive.
True
Which of the following is not an example of turbulent flow?
a river flowing slowly in a straight line
Which of the following is an example of projectile motion?
a thrown baseball
Which of the following line segments on a position versus time graph is physically impossible?
a vertical line
Physics is the study of
a wide variety of phenomena
In which of the following sentences is work used in the scientific sense of the word?
and Rachel pushed hard, but they could do no work on the car.
The motion of a metronome is an example of simple ____________________ motion.
harmonic
Which of the following terms describes a transfer of energy?
heat
A negative value for Q indicates that
heat energy has been lost to the environment.
A campfire is designed to turn chemical potential energy into
heat.
When you rub your hands together vigorously, the kinetic energy of your hand movement is converted mostly into
heat.
The amplitude of a longitudinal wave would be judged by
how far back and forth a particle of the medium vibrates as the wave goes through.
The specific heat capacity measures
how much the temperature is raised for a substance with a specified amount of heat.
A wedge is a form of
inclined plane.
After colliding, objects are deformed and lose some kinetic energy. Identify the type of collision.
inelastic
A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster
is greater down the hill than up the hill.
A force does work on an object if a component of the force
is parallel to the displacement of the object.
What thermodynamic process for an ideal gas system has an unchanging internal energy and a heat intake that corresponds to the value of the work done by the system?
isothermal
A billiard cue ball hits another billiard ball of equal mass straight on and stops. What will the billiard ball do that was hit?
leave at the same velocity and direction as the cue ball had before the collision
A short lever arm produces ______ a long lever arm.
less torque than
The familiar experience of pushing a lawn mower from a concrete surface onto a lawn serves as a model for
light refraction
A lack of precision in scientific measurements typically arises from
limitations of the measuring instrument
A scalar quantity is a quantity that has
magnitude only
One good way to avoid parallax errors in measurement is to
make each measurement from the same viewing angle
What quantity measures the output force of a machine relative to the input force?
mechanical advantage
Which of the following is an area of physics that studies motion and its causes?
mechanics
A mechanical wave requires a(n)
medium through which to travel.
What term is used to describe the vector sum of all the forces acting on an object?
net force
If the Universe were a movie, you would be able to tell whether it was being played in forward or reverse by _______________.
seeing which way the heat flowed; heat always flows from hotter objects to colder ones, never in reverse
The difference between tangential speed and angular speed is that
tangential speed is the speed along a line; angular speed is around a circle.
The force of air molecule collisions over a given area, or pressure, is proportional to
the amount of air in the container.
What does temperature measure?
the average kinetic energy of particles in a substance
A crew member is walking on a tugboat that is pulling a barge. The tugboat is moving at a constant speed upstream in a river that has a constant downstream current. What is at rest relative to the tugboat?
the barge
Kepler's Third Law of Planetary Motion states that the square of a planet's orbital period is proportional to
the cube of the distance between the sun and the planet.
A good example of work done by heat of gases is _________________________.
the internal combustion engine
The period and speed of a planet or satellite is determined by
the mass of the central object and the distance between the central object and the orbiting body.
The hypothesis that a penguin's flippers are more effective than propellers is suggested by the observation of
the penguin's ease of motion in water
The change in an object's momentum is equal to
the product of the force applied to the object and the time interval
If a car passes another going 20 mph faster than the second car, what would you need to know in order to calculate the speed of the second car?
the speed of the first car
What does the net force between two levels in a fluid equal?
the weight of the fluid between the levels
A billiard ball collides with a second identical ball in an elastic head-on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision?
unchanged
Which equation would you use if you know the distance that the projectile will fall, but do not know the time?
v(yf)^2 = -2gy
A mass attached to a spring vibrates back and forth. At the equilibrium position, the
velocity reaches a maximum.
Which of the following line segments on a velocity versus time graph is physically impossible?
vertical line
Which of the following is a form of kinetic energy that occurs within a molecule when the bonds are stretched or bent?
vibrational
Listening to your favorite radio station involves which area of physics?
vibrations and wave phenomena
During an isovolumetric process, which of the following does not change?
volume
When an ideal gas does positive work on its surroundings, which of the gas's quantities increases?
volume
A change in the gravitational force acting on an object will affect the object's
weight.
The values for the efficiency of a machine
will always be between 0 and 1.
Which of the following is not a fluid under normal conditions?
wood
Which of the following is NOT characteristic of wave motion?
work
Power measures how much__________ in a given time interval. In other words, power is the rate of ___.
work is done; work
In an adiabatic process, any change in internal energy must be accompanied by a change in
work.
Which of the following is the best coordinate system to analyze a painter climbing a ladder at an angle of 60° to the ground?
x-axis: horizontal along the ground; y-axis: up and down
When an object is submerged in water, it displaces 30 cm^3 . When its weight is measured, it is the equivalent of 28 g. Will the object float in water?
yes
A skydiver, when free-falling, experiences an acceleration of -9.8 m/s/s. What is her acceleration prior to exiting the airplane? (Assume level flight at constant velocity.)
zero
A toddler wanders away from his mother and walks 20 paces away, and then turns around and walks back to his mother. Using his mother as the frame of reference, the total displacement of the toddler is
zero
If two teams playing tug-of-war pull on a rope with equal but opposite forces, what is the net external force on the rope?
zero
What is the magnitude of the displacement of a windup toy that starts its motion from any position and returns to that position?
zero
A car goes forward along a level road at constant velocity. The additional force needed to bring the car into equilibrium is
zero.
Equilibrium is the state in which the vector sum of all external forces is
zero.
Two rocks are dropped simultaneously and undergo free fall. Compare their displacements after equal intervals of time.
The displacements are equal.
Explain how a dog that has moved can have a displacement of zero.
The dog's initial position and its final position are the same position.
In a mechanical wave, what is the relationship between the energy and the wave's amplitude?
The energy is proportional to the square of the wave's amplitude.
Two bottles are immersed in tubs of water. In one case, the bottle's temperature is 40°C, and the water's temperature is 20°C. In the other case, the bottle's temperature is 55°C, and the water's temperature is 35°C. How does the energy transfer between the bottles and the water for the two cases compare?
The energy transfer is the same for both cases.
If two small beakers of water, one at 70°C and one at 80°C, are emptied into a large beaker, what is the final temperature of the water?
The final temperature is between 70°C and 80°C.
How does the force of static friction on a crate you cannot budge compare to the force you exert on it? Assume that the crate is on a flat surface.
The magnitude of the force of static friction equals the magnitude of the force you exert, and the forces are opposite in direction.
If a system gains in potential energy, what must also be true?
The sum of kinetic energy and internal energy must decrease.
When a drop of ink mixes with water, what happens to the entropy of the system?
The system's entropy increases, and the total entropy of the universe increases.
If energy is transferred as heat from a closed metal container to the air surrounding it, what is true of the initial temperatures of the container and the air?
The temperature of the container is initially greater than the temperature of the air.
A crew member is walking on a tugboat that is pulling a barge. The tugboat is moving at a constant speed upstream in a river that has a constant downstream current. The captain records the upstream speed of the tugboat relative to the river. A dockhand records the tugboat's upstream speed relative to the shore. How do the recorded speeds differ?
The tugboat's speed measured relative to the river will be greater than its speed measured relative to the shore.
In terms of energy, what occurs when a machine does work on an object?
When a machine does work on an object, energy is transferred to that object.
Which are simultaneous equal but opposite forces resulting from the interaction of two objects?
action-reaction pairs
The slopes of the lines in between the plateaus of the phase changes in a temperature vs. energy input graph for water are
all different, as each phase has its own specific heat capacity.
The equation for determining gravitational potential energy is PE(g) = mgh. Which factor(s) in this equation is (are) not intrinsic to an object?
both g and h
The equation for determining gravitational potential energy is PE(g) =mgh. Which factor(s) in this equation is (are) not intrinsic to an object?
both g and h
How are force vectors represented in force diagrams?
by arrows
According to the scientific method, how does a physicist formulate and objectively test hypotheses?
by experiments
Two fluids, which are approximately 90 0 C different in temperature, are in insulated beakers and connected by a conducting rod. Which of the following materials will allow the two fluids to most quickly come to the same temperature?
copper
In the steps of the scientific method, what is the next step after formulating and objectively testing hypotheses?
interpreting results
What is NOT a possible use for physics equations?
introduce new mathematics
If a boundary is fixed and immovable, the waves that bounce off it are
inverted.
A temperature is inserted into pure water at its boiling point. Which of the following readings would indicate something is wrong with the thermometer?
273 degrees K.
A water bed that is 1.5 m wide and 2.5 m long weighs 1055 N. Assuming the entire lower surface of the bed is in contact with the floor, what is the pressure the bed exerts on the floor?
280 Pa
An ant on a picnic table travels 3.0 x 10^1 cm eastward, then 25 cm northward, and finally 15 cm westward. What is the magnitude of the ant's displacement relative to its original position?
29 cm
In a movie, the hero climbs a vertical rope hand over hand to a height of 65 m in a time of 180 s. Assume the hero has a mass of 82 kg. The acceleration of gravity is 9.81 m/s/s. What is the hero's power output?
290 W
Since the usual choice of coordinates uses ______ as the direction away from Earth, the direction of free-fall acceleration is _______because the object accelerates toward Earth.
positive; negative
The stress that builds up along a fault line is a form of
potential energy.
Which of the following is the rate at which energy is transferred?
power
Which of the following is the rate at which work is done?
power
Which of the following terms includes the value of time (expressed as a rate)?
power
In most homes, electricity is transformed into light, heat, and mechanical energy. The rate of such a transformation is referred to as electrical
power.
Kepler's three laws of planetary motion ________ Newton's three laws of motion.
preceded
A pulley that uses 3 strands of rope and 2 wheels, similar to the one in the presentation, has a mechanical advantage of
3.
Three values were obtained for the mass of a metal bar: 8.83 g; 8.84 g; 8.82 g. The known mass is 10.68 g. The values are
precise
For incompressible fluids, density changes little with changes in
pressure.
What is the term for the curved, parabolic path that an object follows when thrown, launched, or otherwise projected near the surface of the Earth?
projectile motion
Which of the following is the motion of objects moving in two dimensions under the influence of gravity?
projectile motion
One end of a taut rope is fixed to a post. What type of wave is produced if the free end is quickly raised and lowered one time?
pulse wave
Which of the following is a single non-periodic disturbance?
pulse wave
A _____ wave is a single traveling disturbance resulting from a motion that is not repeated. A _____ wave is one whose source is repeated motion.
pulse; periodic
A girl pushes a box that has a mass of 450 N up an incline. If the girl exerts a force of 150 N along the incline, what is the mechanical advantage of the incline?
3.0
A 2.0 m long stretched rope is fixed at both ends. Which wavelength would not produce standing waves on this rope?
3.0 m
A 5.3 x 10^3 kg truck moving at 16 m/s strikes a 1.7 x 10^3 kg automobile stopped at a traffic light. The vehicles hook bumpers and skid together at 10.4 m/s. What is the decrease in kinetic energy?
3.0 x 10^4 J
If the air pressure in a tire is measured as 2.0 x 10^5 Pa, and atmospheric pressure equals 1.0 x 10^5 Pa, what pressure does the air within the tire exert outward on the tire walls?
3.0 x 10^5 Pa
A book with a mass of 2.0 kg is held in equilibrium on a board with a slope of 60.0 degrees by a horizontal force. What is the normal force exerted on the book?
39 N
A sled is pulled at a constant velocity across a horizontal snow surface. If a force of 4.0 ? 10^1 N is being applied to the sled rope at an angle 11 ? to the ground, what is the magnitude of the force of friction of the snow acting on the sled?
39 N
What is the momentum of a 130-kg football player running north at 3.0 m/s?
390 kg-m/s north
If the mass in a horizontal mass-spring system was doubled, the elastic potential energy in the system would change by a factor of
0 (no change).
The SI base unit for time is
1 second
A bullet is fired horizontally with a horizontal velocity of 200 m/s from a height of 4.9 meters. How long will it stay in the air, and how far will it travel horizontally? Neglect air resistance.
1 second, 200 m
In 1933, a storm occurring in the Pacific Ocean moved with speeds reaching a maximum of 126 km/h. Suppose a storm is moving north at this speed. If a gull flies east through the storm with a speed of 40.0 km/h relative to the air, what is the velocity of the gull relative to Earth?
132 km/h 72.4 north of east
A cave explorer travels 2.0 m eastward, then 2.4 m northward, and finally 18.0 m westward. What is the magnitude of the net displacement?
16.2 m
How long does it take to travel 725 km at an average speed of 44.0 km/hr?
16.5 hrs
A child on a playground swings through a total of 32°. If the displacement is equal on each side of the equilibrium position, what is the amplitude of this vibration? (Disregard frictional forces acting on the swing.)
16°
What is the fewest number of nodes a standing wave can have?
2
Humans can hear sounds with frequencies from
20 Hz to 20 000 Hz.
Which of the following situations is an example of a visible change in momentum?
A baseball is hit by a bat.
In which of the following scenarios is work done?
A car decelerates while traveling on a flat stretch of road.
In which of the following scenarios is no net work done?
A car travels at constant speed on a flat road.
Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upward along a y-axis.)
A cat jumps from a tree limb to the ground.
How does a liquid differ from a gas?
A liquid has definite volume, unlike a gas.
How does a real heat engine differ from an ideal cyclic heat engine?
A real heat engine is not isolated, so matter enters and leaves the engine.
Two balls of dough collide and stick together. Identify the type of collision.
perfectly inelastic
Which of the following energy forms is associated with an object due to its position?
potential energy
Which of the following is NOT a statement of the second law of thermodynamics?
All processes tend to make things more orderly.
Specific heat is the amount of heat required to _____________________.
raise the temperature of a kilogram of mass one degree K
The internal energy of heat is due to
random motions of the particles of a substance.
Waves arriving at a fixed boundary are
reflected and inverted.
Waves arriving at a free boundary are
reflected but not inverted.
A rubber ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude of the momentum of the rubber ball
remained the same.
A soccer ball collides with another soccer ball at rest. The total momentum of the balls
remains constant.
Simple harmonic motion is vibration about an equilibrium position in which a(n) ____________________ force is proportional to the displacement from equilibrium.
restoring
Is kinetic energy a vector quantity or a scalar quantity?
scalar quantity
Is work a vector quantity or a scalar quantity?
scalar quantity.
Identify the following quantities as scalar or vector: the mass of an object, the number of leaves on a tree, wind velocity.
scalar, scalar, vector
Identify the following quantities as scalar or vector: the speed of a snail, the time it takes to run a mile, the free-fall acceleration.
scalar, scalar, vector
UNIT 4
CHECKPOINT 19
The forces on a body, as outlined in a free-body diagram, seldom change.
False
The order in which vectors are added together is important. Different resultants come from a different sequence of addition.
False
The requirement that Q c > 0 means that __________________, and therefore this energy cannot be used by the engine to do work.
some energy must be transferred as heat to the system's surroundings
The type of friction that operates on an object that is not moving is
static friction.
Which of the following describes a substance in which the temperature and pressure remain constant while the substance experiences an inward transfer of energy?
substance undergoing a change of state
According to the conservation of energy, what is true about the net work and net heat in a cyclic process?
In a cyclic process, the net work equals the net heat.
How would the speed of Earth's orbit around the sun change if Earth's mass increased by 4 times?
It would increase by a factor of 2.
Which of the following is not a widely used temperature scale?
Joule
Which of the following is a direct cause of a substance's temperature increase?
Kinetic energy is added to the particles of the substance.
UNIT 1
LESSON 1
UNIT 3
LESSON 11
What provides the centripetal force for a ball whirled on a string?
tension
UNIT 2
Lesson 10
Which of the following formulas implies that mechanical energy is conserved?
ME(i) = ME(f)
____ is the amount of matter in an object and is an inherent property of an object. _____ is not an inherent property of an object and is the magnitude of the force due to gravity acting on the object.
Mass; Weight
What is the abbreviation of the unit newton?
N
Which of the following is NOT a valid equation for power?
P = KEt, t being the time interval.
An example of convection transfer of heat is
the blast of hot air that meets you as you open the door of a car on a hot day.
The work-kinetic energy theorem states that the total work done on an object is equal to
the change in kinetic energy of the object.
The terms, 0.5 mv(f)^2 - 0.5 mvf(i)^2 , are the same thing as
the change in kinetic energy.
Entropy is a measure of
the disorder in a system
How is conservation of internal energy expressed for an isolated system?
Q=W=0, so deltaU=0 and U i = U f
The difference between displacement and velocity is _____________.
the element of time
In simple harmonic motion, which point(s) exhibit the following characteristics: maximum potential energy, minimum kinetic energy, maximum force and acceleration, minimum velocity?
the extremities of the motion
Thermodynamics studies
the flow of heat.
The negative sign in Hooke's law means that
the force is always pushing the object toward the resting or equilibrium point.
When a hammer strikes a nail, the work done on the hammer contains a negative sign, indicating that
the hammer loses kinetic energy.
The latent heat of melting is more commonly called
the heat of fusion.
When steam condenses into water, the energy that is released is
the latent heat of vaporization.
The length of a vector arrow in a diagram is proportional to what property of the vector?
the magnitude of the vector
The formulas for the period of a pendulum and that of a mass-spring system are similar. The pendulum varies according to the values of the length of the string and the gravitational acceleration. What does the mass-spring system depend on?
the mass and the spring constant
The continuity equation is based upon the simple fact that, in a continuously flowing pipe,
the mass leaving the pipe must equal the mass entering the pipe.
No machine can be made that converts heat entirely to work. Alternately, in terms of entropy change: the entropy of the universe increases in all natural processes." These are both statements of
The Second Law of Thermodynamics.
When a car is moving, what happens to the velocity and acceleration of the car if the air resistance becomes equal to the force acting in the opposite direction?
The acceleration is then zero, and the car moves at a constant velocity
Which statement about the acceleration of an object is correct?
The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object.
Compare the acceleration of a rock in free fall with the acceleration of another rock in free fall dropped a few moments before.
The accelerations are the same.
An ideal heat engine has an efficiency of 50 percent. Which of the following statements is not true?
The amount of energy exhausted as heat equals the energy added to the engine as heat.
What are the units of the coefficient of friction?
The coefficient of friction has no units
If an object is only partially submerged in a fluid, which of the following is true?
The density of the fluid is greater than the density of the object.
Energy transfer as heat between two objects depends on which of the following?
The difference in temperature of the two objects.
After the initial break, two billiard balls of equal mass run directly into each other. The first is going 2.0 m/s; the second 1.0 m/s. Which of the following is a possible outcome of the collision?
The first recoils at 0.3 m/s; the second rebounds at 1.3 m/s.
How does a gas change shape when it is poured from a small flask into a large flask?
The gas expands and changes shape to fill the container.
When a gas is poured out of one container into another container, which of the following does not occur?
The gas keeps its original volume.
A hammer drives a nail into a piece of wood. Identify an action-reaction pair in this situation.
The hammer exerts a force on the nail; the nail exerts a force on the hammer.
The impulse-momentum equation is F t = mv f - mv i . Which of the following statements is the word equivalent of the equation?
The impulse is equal to the change in momentum.
Which statement applies when all of the entropy changes in a process are taken into account?
The increases in entropy are always greater than the decreases.
What is true of the internal energy of an isolated system?
The internal energy is constant, since no energy is transferred in or out.
If friction is the only force acting on an object during a given physical process, which of the following assumptions can be made in regard to the object's kinetic energy?
The kinetic energy decreases.
What happens to an object in motion when it experiences a nonzero net external force?
The object experiences an acceleration.
What can you determine about the average kinetic energy of the particles in two objects that are in thermal equilibrium?
The particles in each object have the same average kinetic energy and temperature.
An object is lowered into a deep hole in the ground. How does the potential energy of the object change?
The potential energy decreases.
Why does the lift on an airplane wing increase as the speed of the airplane increases?
The pressure above the wing becomes less than the pressure below the wing.
What does Bernoulli's principle state will happen to the pressure in a fluid as the speed of the fluid increases?
The pressure in the fluid will decrease.
Why does an ideal fluid move faster through a pipe with decreasing diameter?
The pressure within the fluid decreases.
In the presence of friction, not all of the work done on a system appears as mechanical energy. What happens to the rest of the energy provided by work?
The remaining energy causes an increase in the internal energy of the system.
Two identical masses are lifted to the same height. The first is taken up by a rocket and the second by a balloon. Which of the following statements about the events is true?
The rocket and the balloon performed equal amounts of work.
Which of the following is a reason that water is used as the heat receiver in a simple calorimeter?
The specific heat capacity of water is well-known.
A hockey stick hits a puck on the ice. Identify an action-reaction pair in this situation.
The stick exerts a force on the puck; the puck exerts a force on the stick.
Which of the following is not a way in which a cyclic process resembles an isothermal process?
The temperature of the system remains constant throughout the process.
What condition is necessary for two bodies that are in physical contact with each other to be in thermal equilibrium?
The temperature of the two objects must be the same.
Why is the triple point of water used as a standard for temperature measurement?
The triple point is only evident under very defined and narrow conditions.
If the magnitude of a vector component is the magnitude of the vector, what is the orientation of the vector with respect to that axis?
The vector is parallel to that axis.
A boat produces a wave as it passes an aluminum can floating in a lake. Why is the cans not moved along in the direction of wave motion?
The water wave is a disturbance moving through the water, but the water (the medium) is not carried forward with the wave.
Two billiard balls of equal weight are heading for a collision. What can be said about their status after the collision?
Their total momentum will be the same.
A free-falling skydiver is converting gravitational potential energy into the kinetic energy of motion.
True
Which of the following is NOT an equivalent expression for V(ad)?
V(ab) - V(db)
Which equation describes the net work done for a complete cycle of a heat engine?
W net = Q h --Q c
What is a projection of a vector along an axis of a coordinate system called?
a component of the vector
In physics, work is the result of a force that causes
a displacement.
In general, buoyant forces arise from
a reactionary force to gravity.
A force that produces a large movement in a kickball will produce ______ movement in a bowling ball.
a smaller
When a rope is attached to a fixed barrier, and waved at the same amplitude and period,
a standing wave will result.
How is conservation of internal energy expressed for a system during an isothermal process?
deltaT = 0, so deltaU = 0; therefore, deltaU = Q - W = 0, or Q = W
A hiker uses a compass to navigate through the woods. Identify the area of physics that this involves.
electromagnetism
The centripetal force on an object in circular motion is
in the plane of the object's motion and perpendicular to the tangential speed.
Almost all collisions in the everyday world are of what type?
inelastic
Bomb calorimetry takes place in a rigid container. Therefore, bomb calorimetry is a _______ process.
isovolumetric
In simple harmonic motion, the speed of the moving object will be highest when
it passes the equilibrium point.
A calorimeter is used to determine the specific heat capacity of a test metal. If the specific heat capacity of water is known, what quantities must be measured?
metal mass, water mass, initial and final temperatures of metal and water
At the apex, or high point, of its flight, a bullet fired upward has
no velocity upward or downward
A floating object experiences a net force
of zero in the vertical direction.
Hertz (Hz) is a measure of frequency. One hertz equals
one cycle per second.
What determines whether an object will sink or float?
the net force, or the apparent weight
If movement to the right of the frame of reference is designated as positive, a speed of -20 km/hr indicates that
the object is moving to the left of the frame of reference at 20 km/hr
If gravity and the normal force are the only vertical forces acting upon an object, and the vertical component of the normal force is equal to the gravitational force, then
the object will not move up or down.
The power rating of a machine indicates
the rate at which it does work on an object.
Acceleration is defined as
the rate of change of velocity
Instantaneous velocity is indicated on a displacement-time graph by
the slope of a tangent line touching the displacement curve only at the instant in question
In a simple calorimeter, what would you have to know in order to calculate the amount of heat absorbed by the test material before it was dropped into the water of the calorimeter?
the specific heat capacity of water
The potential energy of a position of a spring depends on two factors,
the spring constant and the distance away from the relaxed position of the spring.
When two mechanical waves coincide, the amplitude of the resultant wave is always ____ the amplitudes of each wave alone.
the sum of
In situations where mechanical energy is conserved, the mechanical energy is always equal to
the sum of the potential and kinetic energies.
What is a resultant?
the sum of two or more vectors
An object put in water experience a buoyant force that depends on _____________________________________.
the volume of the object
When pressure is applied to the top of a water column, ______________________________.
the water pressure in the entire column increases
To find the speed of the wave, you would need to know the period or frequency, and
the wavelength.
What are materials that easily transfer energy as heat called?
thermal conductors
To describe motion, the frame of reference must be assumed to be
unmoving
If you wish to create a transverse wave in a rope attached at one end, you would move the other end
up and down, or right and left.
If a nut cannot be budged with the wrench you are using, what is the easiest way to get more torque on the nut?
use a longer wrench
Which of the following values does NOT affect the force of gravity between two objects?
whether they are solids or gases
Mechanical energy is not always conserved. But when the change in internal energy is taken into account along with changes in kinetic and potential energy,
the total energy is conserved.
The cosine of 90 degrees is 0. Consequently, when a force is applied perpendicularly to the motion of an object,
the work done is zero.
"The net work done by the net force acting on an object is equal to the change in the kinetic energy of the object" is a statement of
the work-kinetic energy theorem.
The component A(x) of a vector A lies along what axis?
the x-axis
Materials will float in a fluid only if
their average density is less than that of the fluid.
Steam burns more severely at 100 degrees C than does liquid water at the same temperature because
there is more latent heat in the steam than in the liquid.
A warm day has a high temperature of 38.1°C. What is this temperature in degrees Fahrenheit?
100.6°F
The density of water is approximately 1000 kg per cubic meter. Free-fall acceleration is approximately 10 m/s/s. What is the approximate gauge pressure (above atmospheric pressure) at the bottom of a 10 meter pool of water?
10^5 Pa or 1 atm
If the magnitude of a vector component equals the magnitude of the vector, then what is the magnitude of the other vector component?
zero
The symbol mm represents a
millimeter
An electric drill bores through a 0.111 kg piece of copper in 22.9 s. Find the increase in the temperature of the copper if the drill operates at 50.8 W. Assume that the drill does not increase in temperature. (c p = 387 J/kg*C)
0.111°C
A couch with a mass of 1.00 x 10 kg is placed on an adjustable ramp connected to a truck. As one end of the ramp is raised, the couch begins to move downward. If the couch slides down the ramp with an acceleration 0.79 m/s^2 when the ramp angle is 12.0 degrees, what is the coefficient of kinetic friction between the ramp and the couch? (g = 9.81 m/s^2)
0.131
According to the second law of thermodynamics, some of the energy added as heat to an energy (Q h) must be removed from the engine as heat to a substance at a lower temperature (Q c). Q c is therefore greater than 0. Efficiency is equal to 1-(Q c/ Q h), and because Q c/Q h must be greater than 0, the efficiency must be less than
1.
A student uses a scale to weigh a cube of metal. She finds a weight of 5.73 N. When she weighs the cube while it is immersed in water, the scale reads 4.67 N. Find the buoyant force acting on the cube and the density of the cube. The density of water is 1.00 x 10^3 kg/m^3 .
1.06 N; 5.41 x 10^3 kg/m^3
What force is required to accelerate a 0.5 kg hockey puck at 20 m/s/s?
10 N
A runner at a track meet has a speed of 1.5 m/s and a mass of 73 kg. What is the runner's momentum?
110 kg-m/s
What is the potential energy of a 150-kg rock perched on a 10. m high cliff? (Use 9.8 m/s/s as the gravitational acceleration.)
15 000 J
A mass of 0.55 kg attached to a vertical spring stretches the spring 36 cm from its equilbrium position. What is the spring constant?
15 N/m
A baseball is hit directly upward off the bat at 19.62 m/s. How far will it go up before it begins to fall? Disregard air resistance and use -9.81 m/s/s as the value of gravitational acceleration.
19.6 m
A student attaches a rope to a 20.0 kg box of books. He pulls with a force of 90.0 N at an angle of 30 degrees with the horizontal. To make his job easier, he oiled the bottom of the box, reducing the coefficient of friction to 0.250. What is the magnitude of the acceleration of the box?
2.0 m/s/s
Calculate the following, and express the answer in scientific notation with the correct number of significant figures: (0.82 + 0.042)(4.4 * 10^3)
3.8 * 10^3
A penny is kicked horizontally off the top of a vertical cliff and falls 100 m downward. It hits the ground 18 m from the cliff base. Find the speed of the penny as it is kicked off the cliff. (Gravitational acceleration = -9.81 m/s/s)
3.8 m/s
A lever uses a 50 N downward force to lift a 200 N object 1 meter. Since the work done on either end of the lever is equal, but opposite in direction, how far down did the 50 N force have to push?
4 meters
In women's fastpitch softball, the pitcher throws the ball at 30.0 m/s. The ball has a mass of 1.08 kg. What is the kinetic energy of the softball?
486 J
If the displacement of a horizontal mass-spring system was doubled, the elastic potential energy in the system would change by a factor of
4.
What is the kinetic energy of a 1.5 x 10^3 kg car traveling at 25 m/s?
4.7 x 10^5 J
A 20-kg cart rolling down a ramp at 2 meters per second has ____ joules of kinetic energy.
40
There are six books in a stack, and each book weighs 5 N. The coefficient of static friction between the books is 0.2. With what horizontal force must one push to start sliding the top five books off the bottom one?
5 N
To subtract the vector, 5 m north, you would add the vector
5 m south
A boat moves at 12.00 m/s relative to the water. If the boat is in a river where the current is 9.00 m/s, how long does it take the boat to make a complete round trip of 1400.0 m upstream followed by 1400.0 m downstream?
5.34 x 10^2 seconds
Convert 5.52 * 10^8 g to kilograms using scientific notation
5.52 * 10^5
Calculate the following, and express the answer in scientific notation with the correct number of significant figures: 21.4 + 15 + 17.17 + 4.003
5.8 * 10^1
A 5.23 x 10^2 kg object is attached by a rope through a pulley to a paddle-wheel shaft that is placed in a well-insulated tank holding 25.3 kg of water. The object is allowed to fall, causing the paddle wheel to rotate, churning the water. Assume the object falls a vertical distance of 1.23 x 10^2 m at a constant speed, that all of the change in internal energy is conveyed to the water, and that it takes 4186 J to raise the temperature of each kilogram of water by 1.00*C. What is the temperature change of the water? (g = 9.81 m/s^2)
5.96°C
What is the average power supplied by a 60.0 kg person running up a flight of stairs a vertical distance of 4.0 m in 4.2 s?
560 W
Multiplying the vector, 3 meters west, by -2, results in the vector,
6 meters east
One process accomplishes 24 joules of work in 2 seconds. Another process does the same amount of work in 4 seconds. What is the difference in power between the two processes?
6 watts
What is the period of the pendular motion of a mass attached to a 9.8 meter string? (Gravitational acceleration = 9.8 m/s/s)
6.28 seconds
What would be the period of a 33 kg mass dangling from a spring with a spring constant of 33 N/m?
6.28 seconds
A quarterback takes the ball from the line of scrimmage and runs backward for 1.9 × 101 m. He then runs sideways, parallel to the line of scrimmage, for 17 m. Next, he throws the ball forward 7.8 × 101 m, perpendicular to the line of scrimmage. The receiver is tackled immediately. How far is the football displaced from its original position?
62.0 m
Water flows over a section of Niagara Falls at a rate of 1.30 x 10^6 kg/s and falls 49.5 m. What is the power of the waterfall?
631 MW
A box weighing 210 N is pushed up an inclined plane that is 2.0 m long. A force of 140 N is required. If the box is lifted 1.0 m, what is the efficiency of the inclined plane?
75%
While following directions on a treasure map, a person walks 66.0 m south, then turns and walks 7.60 m east. Which single straight-line displacement could the person have walked to reach the same spot?
66.5 m at 83.4° south of east
Liquid oxygen has a temperature of -189°C. What is this temperature in kelvins?
84 K
The surface temperature of Venus is 737 K. What is this temperature in degrees Fahrenheit?
867°F
On a simple inclined plane, about 10% of the force is dissipated due to friction. What is the efficiency of the inclined plane?
90%
Which of the following statements is always true?
Pressure always increases when force increases or the area acted on decreases
Until the middle of the 16th century, most people believed ____ was at the center of the universe.
Earth
A ball is dropped from a person's hand and falls to Earth. Identify an action-reaction pair in this situation.
Earth exerts a force on the ball; the ball exerts a force on Earth.
_____ do not have a definite shape. Solid objects cannot flow, and consequently have a definite shape
Fluids
Another way to state Newton's Third Law is
For every action there is an equal but opposite reaction
______is the motion of an object falling with a constant acceleration due to gravity in the absence of air resistance.
Free fall
Which of the following confirms that gravitational mass and inertial mass are equivalent?
Free-fall acceleration is the same at all points where the gravitational field strength is the same.
Why does sandpaper get hot when it is rubbed against rusty metal?
Friction between the sandpaper and metal increases the temperature of both.
According to the second law of thermodynamics, which of the following statements about a heat engine operating in a complete cycle must be true?
Heat from a high-temperature reservoir cannot be completely converted to work.
The SI unit for force is the ____, which is kg-meters/second^2 .
Newton
inertia
Newton's First Law
acceleration
Newton's Second Law
thrust
Newton's Third Law
Action-reaction pairs are a natural result of
Newton's Third Law.
Is power a vector quantity or a scalar quantity?
Power is a scalar quantity.
The heat of a system is generally represented by the letter,
Q .
How is the conservation of a system's internal energy mathematically expressed for an adiabatic process?
Q = 0 for an adiabatic process, so deltaU = -W.
How is conservation of internal energy expressed for a system during an adiabatic process?
Q = 0, so deltaU = -W
Which of the following statements about floating objects is correct?
The buoyant force equals the object's weight.
In which of the following sentences is work used in the everyday sense of the word?
Sam and Rachel worked hard pushing the car.
Which is a scalar quantity, instantaneous velocity or average speed?
average speed
What is the ratio of an object's displacement to the time interval during which the displacement occurred?
average velocity
Which of the following energy forms is not involved in hitting a tennis ball?
chemical potential energy
A(n) _________ is a thermodynamic process in which a system returns to the same conditions under which it started, so that there is no change in the system's internal energy.
cyclic process
Which of the following does NOT significantly affect the magnitude of the frictional force?
location on Earth's surface
According to Newton's second law, when the same force is applied to two objects of different masses,
the object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration.
Diagrams are not designed to
measure an event or situation
Work is done when
the displacement is not zero
Torque is a
vector quantity.
In general, Fnet equals
ΣF
A substance registers a temperature change from 20°C to 40°C. To what incremental temperature change does this correspond?
36°F
How much power is required to lift a 2.0 kg mass at a speed of 2.0 m/s?
39 J
A 3.0 m long stretched string is fixed at both ends. If standing waves with a wavelength of two-thirds L are produced on this string, how many nodes will be formed?
4
A man uses a lever to lift a 200 N block. He applies 50 N to the lever to lift the block. What is the mechanical advantage of the lever?
4
A compressed gas expands by pushing a piston against atmospheric pressure. In the process, it does 2.00 x 10 5 J of work and the internal energy decreases by 1.50 x 10 5 J. How much energy is lost to the surroundings as heat?
5.0 x 10^4 J
In the statement Δ y = 4.9(Δ t ) 2 , the units of y are meters and the units of t are seconds. Which of the following is the best estimate for how much y changes when t increases by 3 seconds?
50 meters
The radius of the Earth is approximately 4000 miles. If an astronaut weighs 200 pounds on the surface of the Earth, how much would he weigh at an altitude of 4000 miles (8000 miles from Earth's center)?
50 pounds
The radius of Earth is 6 370 000 m. Express this measurement in km in scientific notation with the correct number of significant digits.
6.73 * 10^3
The "trigger" piston in a small water pistol has an area of 2.8 x 10^-5 m^2 . The area of the water column that is ejected from the nozzle is 1.9 x 10^-7 m^2 . If the force on the trigger is 1.0 N, what is the force on the water column?
6.8 x 10^-3 N
A container of gas is at a pressure of 3.8 x 10^5 Pa. How much work is done by the gas if its volume expands by 1.8 m^3?
6.8 x 10^5 J
If a plane is flying at 600 miles per hour due east through the atmosphere and is experiencing a tailwind of 40 miles per hour, what is its speed relative to the ground?
640 mph
A late traveler rushes to catch a plane, pulling a suitcase with a force directed 30.0? above the horizontal. If the horizontal component of the force on the suitcase is 60.6 N, what is the force exerted on the handle?
70.0 N
What is the potential energy of a 1.0 kg mass 1.0 m above the ground?
9.8 J
Which of the following situations is an example of a significant change in momentum?
A tennis ball is hit into a net.
A car with a mass of 2500 kg is skidding on dry concrete. The horizontal force on the car is 21 000 N. Assume the acceleration of gravity is 9.81 m/s/s. What is the coefficient of kinetic friction between the tires and the concrete?
0.86
A certain string that is 1.0 m long vibrates with a standing wave having three nodes and two antinodes. What is the wavelength of this standing wave?
1.0 m
A computer uses 120 volts and 0.90 amps; a lamp also uses 120 volts, but only 0.20 amps. Over a 12 hour period, what is the difference between the two in kilowatt hours used?
1.01 kwh
The net force on a golf cart is 390 N north. If the cart has a total mass of 270 kg, what are the magnitude and direction of the cart's acceleration?
1.4 m/s/s north
A closed vessel can sink to a depth of 20.0 m in water (n w = 1.00 g/cm^3) before the external pressure crushes it. To what depth could this same container be immersed in a deep vat of mercury (n Hg = 13.6 g/cm^3) without it being crushed?
1.47 m
George V Coast in Antarctica is the windiest place on Earth. Wind speeds there can reach 3.00 x 10^2 km/h. If a research plane flies against the wind with a speed of 4.50 x 10^2 km/h relative to the wind, how long does it take the plane to fly between two research stations that are 250 km apart?
1.7 hr
If T is the period of harmonic motion, its frequency, f, is given by
1/ T .
Which of the following is equivalent to a decimeter?
100 mm
Two snowballs with masses of 0.48 kg and 0.81 kg, respectively, collide head-on and combine to form a single snowball. The initial speed for each is 14 m/s. If the velocity of the new combined snowball is 2.4 m/s after the collision, what is the decrease in kinetic energy?
122 J
How high will a bullet go fired upward at 50.0 m/s? (Hint: The bullet will be as high as it will go when v f = 0.00.) (Use -9.81 m/s/s for gravitational acceleration.)
127 meters
A sled traveling at a speed of 3.0 m/s^2 slows to a stop 4.0 m from the point where its passenger rolled off. What is the magnitude of the horizontal net force that slows the 110 N sled? (Assume a(g) = 9.81 m/s^2)
13 N
While exploring the outer reaches of the solar system, an equipment malfunction leaves an astronaut at rest halfway between an asteroid and her spaceship. Fortunately, she has her prospecting hammer handy. By throwing the hammer directly away from the spaceship, she propels herself toward the spaceship at 0.25 m/s. The mass of the astronaut together with her spacesuit and gear is 150 kg. The hammer has a mass of 3.0 kg. What speed does the hammer have?
13 m/s away from the spaceship
A toy car is given an initial velocity of 7.0 m/s and experiences a constant acceleration of 1.0 m/s^2. What is the final velocity after 6.0 s?
13.0 m/s
A three-tiered birthday cake rests on a table. From bottom to top, the cake tiers weigh 15 N, 8 N, and 6 N, respectively. What is the magnitude and direction of the normal force acting on the base of the second tier?
14 N, upward
Tarzan steps out of his house and grabs a hanging vine to swing to the ground. If his house is 11.3 m above the ground, what is Tarzan's speed when he reaches the ground? Assume that there is no friction, and that Tarzan has a mass of 105 kg.
14.9 m/s
A pendulum swings through a total of 28°. If the displacement is equal on each side of the equilibrium position, what is the amplitude of this vibration? (Disregard frictional forces acting on the pendulum.)
14°
A jogger runs 7.0 blocks due east, 9.0 blocks due south, and another 5.0 blocks due east. Assume all blocks are of equal size. What is the jogger's net displacement?
15.0 blocks
Energy is transferred as heat between two objects, one with a temperature of 5°C and the other with a temperature of 20°C. If two other objects are to have the same amount of energy transferred between them, what might their temperatures be?
17°C and 32°C
Two ice-hockey players simultaneously strike a puck with their sticks. The stick of one player exerts an eastward force on the puck of 15 N. The other player's stick exerts a northward force of 11 N on the puck. Assuming that there is no frictional force between the puck and the ice, what is the magnitude of the net horizontal force on the puck?
19 N
Two balls on a frictionless surface collide elastically head-on. The first ball has a mass of 0.015 kg and an initial velocity of 3.5 m/s to the right, while the second ball has a mass of 0.022 kg and an initial velocity of 4.0 m/s to the left. The final velocity of the first ball is 5.4 m/s to the left. What is the final velocity of the second ball?
2.1 m/s to the right
A horse trots past a fencepost located 14 m to the left of a gatepost. It then passes another fencepost located 15 m to the right of the gatepost 14 s later. What is the average velocity of the horse?
2.1 m/s, to the right
A small airplane flies at a velocity of 106 km/h toward the south as observed by a person on the ground. The airplane pilot measures the velocity of the plane with respect to the air as 129 km/h south. What is the velocity of the wind that affects the plane?
23 km/h north
A bullet is shot upwards with an initial velocity of 100. m/s. About how far will it go up in 3.0 seconds? (Use -9.8 m/s/s for gravitational acceleration.)
260 meters
A 200. horsepower car is speeding down a track at 200. km/hr. What is the net force being exerted on the car? (1 horsepower = 746 watts; 1 hour = 3600 seconds)
2690 N
UNIT 6
CHECKPOINT 27
Impulse is defined as
change in momentum
The heat of vaporization measures the amount of heat required to
completely change a liquid into a gas.
The use of fiberglass insulation in the outer walls of a building is intended to minimize heat transfer through what process?
conduction
Two mechanical waves that have positive displacements from the equilibrium position meet and coincide. What kind of interference occurs?
constructive
Friction is considered a _______force.
contact
A free-body diagram represents all of the following except
forces exerted by the object.
Which stage of the scientific method makes an educated guess as to the cause of natural events?
formulating a hypothesis
How many significant digits does 40.60 have?
four
How many significant figures are there in the measurement readout, 501.0?
four
Which of the following is a coordinate system for specifying the precise location of objects in space?
frame of reference
Air is sucked into an internal combustion engine. When it enters the engine, it is sucked into a wide-mouthed collector area, passed through a filter, and then goes through a small tube into the cylinders. Where will the air pressure be the least?
in the tube before entering the cylinder
A set of measurements (3.0, 3.1, 2.9, and 3.0) are made and compared to the accepted value, which is 3.8. The measurements are
inaccurate
Which of the following is a way to improve the efficiency of a heat engine?
increase Q c
When you turn a corner too fast in your car, you are thrown against the door. What is it that pushes you against the door?
inertia
Which of the following is NOT a force that is found in almost all free-body diagrams?
inertia
Which of the following is the tendency of an object to maintain its state of motion?
inertia
Which of the following words encodes the concept of Newton's First Law of Motion?
inertia
An object's tendency to resist acceleration is measured by the object's
inertial mass.
Blowing up a balloon changes the volume of the inner portion of the balloon, but no heat energy is transferred. The changing volume constitutes work. Which of the following do NOT describe the process of blowing up a balloon?
isovolumetric
Which thermodynamic process takes place at constant volume so that no work is done on or by the system?
isovolumetric
Force can only be seen by
its effect upon the motion of matter.
A newton is equivalent to which of the following quantities?
kg x m/s^2
What are the SI units for momentum?
kg*m/s
Which of the following is an expanded definition of power?
kg-m^2/s^3
According to the equation for pressure, which of the following would NOT be a usable unit of pressure?
kg/cm
Which of the following is not an example of units for expressing pressure?
kg/m^2
The two components of mechanical energy are
kinetic and potential energy.
Heat is a form of
kinetic energy
In elastic collisions, ___________ is conserved.
kinetic energy
The main difference between kinetic energy and potential energy is that
kinetic energy involves motion, and potential energy involves position.
The amount of force equal to 1 kg x m/s^2 defines what SI unit?
newton
A train moving at a constant velocity of 300 km/hr experiences
no acceleration
A standing wave is created in a certain string. Certain points on the string do not appear to be vibrating, but instead seem to be standing still. These points are called ____________________.
nodes
How long does it take a 19 kW steam engine to do 6.8 x 10 7 J of work?
one hour
Which of the following is equivalent to one watt?
one joule/second
Breaking a vector into two components is given what term?
resolving the vector
Two vectors are drawn by using arrows. The length of the arrow is proportional to the magnitude of the vector, and the direction is indicated by the angle the arrow points away from vertical. When the two vectors are placed so that the head of one touches the tail of the other, a third vector can be drawn from the tail of the first to the head of the second. The third vector is called the
resultant
Which of the following situations does NOT largely conserve mechanical energy?
sanding a block of wood
Which of the following is a physical quantity that has a magnitude but no direction?
scalar
In the following sentence, is the everyday meaning or the scientific meaning of work intended? A bulldozer does work lifting a load.
scientific meaning
Which of the following is NOT a fluid?
solids
In the equation for Hooke's Law, F elastic = -kx, the term k represents the ______________ of a spring.
spring constant
When two waves meet, they combine according to the ____________________ principle.
superposition
When two waves occupy the same space at the same time, they are said to be in
superposition.
How does a scientist reduce the frequency of human error and minimize a lack of accuracy?
take repeated measurements, use the same method of measurement, and maintain instruments in good working order
What term describes a change in the speed of an object in circular motion?
tangential acceleration
Which of the following features of a given pendulum changes when the pendulum is moved from Earth's surface to the moon?
the restoring force
Standing waves are produced by periodic waves of
the same frequency, amplitude, and wavelength traveling in opposite directions.
As an object falls toward Earth,
the upward acceleration of Earth is negligible because of its large mass.
In the equation form of Newton's second law, ∑F = ma, what does ∑F represent?
the vector sum of the external forces acting on the object
According to the scientific method, why does a physicist make observations and collect data?
to ask a question
Why is the first term of the vertical distance formula multiplied by the sine of the angle when the projectile is launched at an angle?
to deal exclusively with the vertical component of the motion
Why do physicists use models?
to explain the basic features of complex phenomena
The _______method of adding vectors requires that you align the vectors, tail to tip, by moving them parallel to their original orientations. The resultant vector is an arrow drawn from the tail of the first vector to the tip of the last vector.
triangle
Which of the following properties is not characteristic of an ideal fluid?
turbulent flow
Turbulent flow is the result of internal friction in a fluid; therefore, an ideal fluid does NOT have
turbulent flow.
The superposition of mechanical waves can be observed in the movement of
water waves in a ripple tank.
The equation for vertical distance of an item in projectile motion on the surface of Earth is ____________. (Remember that the gravitational acceleration near the surface of Earth is -9.8 m/s^2.)
y(f) = y(i) + (vi)t - 4.9t^2 y = v^(2/2) d =mgh
For an object to be in equilibrium, the net force acting on the object must have what value?
zero
Two billiard balls of equal mass are traveling straight toward each other with the same speed. They meet head-on in an elastic collision. What is the total momentum of the system containing the two balls before the collision?
zero
Which of the following equations summarizes the Pythagorean theorem?
a^2+b^2=c^2
A net force of 6.8 N accelerates a 31 kg scooter across a level parking lot. What is the magnitude of the scooter's acceleration?
0.22 m/s^2
Air exerts a force on a leaf as it falls from a tree to Earth. Is the work done on the leaf positive, negative, or zero?
negative
If a runner moves from a positive position to a negative position, is the runner's displacement negative or positive?
negative
A simple machine
reduces the force needed to perform work.
What is the speed of an object at rest?
0.0 m/s
Which of the following is not a unit of heat energy?
ATP
Which of the following statements does not describe force?
Force causes objects at rest to remain stationary.
Why is force not a scalar quantity?
Force has both magnitude and direction
In a free-body diagram of an object, why are forces exerted by the object not included in the diagram?
Forces exerted by the object do not change its motion.
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
The car speeds up.
UNIT 3
LESSON 14
Which of the following principles is NOT associated with fluid pressure?
Murphy's law
What happens when a person blows between two paper cups that are hung by strings 10 cm apart?
The cups move toward each other.
In a physics equation, what does it mean when a letter is italicized?
The letter represents a variable
A frequency of 10 Hz (cycles per second) is the same thing as a period of
0.1 seconds.
A baseball is hit directly upward off the bat with an initial upward velocity of 19.62 m/s. How long will its upward flight continue? Disregard air resistance and use -9.81 m/s/s as the value of gravitational acceleration.
2 seconds
A 0.5 kg pendulum at the bottom of its swing is going 3 m/s. What is its kinetic energy?
2.3 J
Ball A has triple the mass and speed of ball B. What is the ratio of the kinetic energy of ball A to ball B.
27
What is the temperature of a system in thermal equilibrium with another system made up of ice and water at 1 atm of pressure?
273 K
Tripling the displacement from equilibrium of an object in simple harmonic motion will change the magnitude of the object's maximum acceleration by what factor?
3
What temperature on the Celsius scale is the equivalent of 87.3°F?
30.7°C
A car runs into a stopped car in front of it. The cars stick together. The first car was traveling 6 m/s when the collision occurred. The first car had a mass of 2000 kg. The other car had a mass of 1000 kg. At what velocity will the two cars travel forward immediately after the collision?
4 m/s
A hiker walks 4.5 km at 45 degrees, then 4.5 km at -45 degrees. Find the magnitude and direction of her displacement from where she started.
6.4 km at 0 degrees
If the flow rate of a liquid is measured at 8.0 x 10^3 m^3/s going through a 20.0 m radius pipe, which of the following is the average fluid velocity in the pipe?
6.4 m/s
For the winter, a duck flies 10.0 m/s due south against a gust of wind with a speed of 2.5 m/s. What is the resultant velocity of the duck?
7.5 m/s south
By what factor should the length of a simple pendulum be changed in order to triple the period of vibration?
9
Which of the following is another way to state Newton's Second Law of Motion?
F = dP/dt where F is force, dP is the change in momentum, and dt is the time interval.
If F is the net external force, m is the mass, and a is the acceleration of a designated body, then
F = ma.
The formula for computing the coefficient of friction is
F(f) = uF(n)
How can an object accelerate without changing speed?
It can change direction
A heat engine has taken in energy as heat and used a portion of it to do work. What must happen next for the engine to complete the cycle and return to its initial conditions?
It must give up energy as heat to a lower temperature so work can be done on it.
How would the speed of Earth's orbit around the sun change if Earth's distance from the sun increased by 4 times?
It would decrease by a factor of 2.
In the equation Fnet = ma, what is the direction of the acceleration?
The acceleration is in the direction of Fnet.
If the position of a car does not change with respect to a fixed frame of reference, describe the motion of the car.
The car is at rest (not moving).
When comparing the momentum of two moving objects, which of the following is correct?
The less massive object will have less momentum if the velocities are the same.
If the magnitude of a vector component is zero, what is the orientation of the vector with respect to that axis?
The vector is perpendicular to that axis.
What are the units of efficiency?
There are no units, since the number is a ratio.
Why does a balloon expand when connected to a flask where water is being heated?
Thermal expansion causes the air and steam to press against the balloon.
Which of the following is not an example of approximate simple harmonic motion?
a ball bouncing on the floor
A screw is ___________________________________.
a inclined plane in a circle
Which of the following is NOT a component of both displacement and velocity?
acceleration
Air cools as it escapes from a diver's compressed air tank. What kind of process is this?
adiabatic
An astronaut in an orbiting spacecraft seems weightless because
both the spacecraft and the astronaut are in free fall
A standing wave is produced by plucking a string. The points along the plucked string that appear not to be vibrating are produced by ____________________ interference.
complete destructive
A simple pendulum swings in simple harmonic motion. At maximum displacement,
the acceleration reaches a maximum.
In a 30-60-90 degree right triangle, the side adjacent to the 60-degree angle is half the length of the hypotenuse. Therefore, the cosine of 60 degrees is
0.5
What is the temperature of a system in thermal equilibrium with another system made up of water and steam at 1 atm of pressure?
100°C
If the digital readout of a measurement is 17.250, and the limit of significant figures is three, how should the measurement be reported?
17.2
A force of 230 N applied on a hydraulic lift raises an automobile weighing 6500 N. If the applied force is exerted on a 7.0 m^2 piston, what is the area of the piston beneath the automobile?
2.0 x 10^2 m^2
A rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a centripetal acceleration of 3.0. m/s/s. If the length of the rope is 2.1 m, at what speed would she be going if she jumped off the tire?
2.5 m/s
A bowling ball with a mass of 1.6 kg is rolling down the bowling lane at a velocity of 1.6 m/s. What is its momentum (most correct answer)?
2.6 kg-m/s down the bowling lane.
Calculate the following, and express the answer in scientific notation with the correct number of significant figures: 10.5 x 8.8 x 3.14
2.9 * 10^2
The temperature of an object is measured as 489.5 K. What is this temperature in degrees Celsius?
216.4°C
A golf ball is hit and given a horizontal velocity of 75 m/s. It stays in the air for 3 seconds. How far does it go before it hits the ground?
225 m
An automobile travels in a positive direction for 20 minutes. At the end of the 20 minutes, the automobile is 10 km further away from the frame of reference in a positive direction. What was the average velocity of the automobile?
30 km/hr
According to legend, to determine whether the king's crown was made of pure gold, Archimedes measured the crown's volume by determining how much water is displaced. The density of gold is 19.3 g/cc. If the crown's mass was 6.00 x 10^2 g, what volume of water would have been displaced if the crown was indeed made of pure gold?
31.1 cc
What is the temperature increase of 6.4 kg of water when it is heated by a 770 W immersion heater for exactly 18.8 min? (c p = 4186 J/kgC)
32°C
A force of 5 N and a force of 15 N acting on an object can produce the following net forces except
5 N.
UNIT 3
LESSON 13
UNIT 1
LESSON 2
UNIT 4
LESSON 20
UNIT 5
LESSON 22
UNIT 5
LESSON 23
UNIT 5
LESSON 24
UNIT 5
LESSON 25
UNIT 6
LESSON 28
UNIT 6
LESSON 29
UNIT 6
LESSON 30
UNIT 1
LESSON 4
UNIT 1
LESSON 5
UNIT 2
LESSON 6
UNIT 2
LESSON 7
UNIT 2
LESSON 8
UNIT 2
LESSON 9
An ice skater moving at 10.0 m/s coasts to a halt in 1.0 x 10^2 m on a smooth ice surface. What is the coefficient of friction between the ice and the skates?
0.051
A single force acts on an object. The components of this force act along the +x-axis and the -y-axis. The single force that will bring the object into equilibrium has components that act along the
-x-axis and +y-axis.
A worker does 25 J of work lifting a bucket, then sets the bucket back down in the same place. What is the total net work done on the bucket?
0 J
An ideal gas system is maintained at a constant volume of 4 L. If the pressure is constant, how much work is done by the system?
0 J
An ideal gas system undergoes an adiabatic process in which it expands and does 20 J of work on its environment. How much energy is transferred to the system as heat?
0 J
The density of water is 1.00 grams/cm^3 . There are one million cubic centimeters in a cubic meter. How many kilograms will one cubic meter of water be?
1000
A fan cart with a total mass of 100 kg accelerates to the west at 10 m/s/s. What is the magnitude and direction of the net external force on the cart?
1000 N to the west
A waitperson carrying a tray with a platter on it tips the tray at an angle of 12? below the horizontal. If the gravitational force on the platter is 5.0 N, what is the magnitude of the force parallel to the tray that tends to cause the platter to slide down the tray? (Disregard friction.)
1.0 N
If 2.0 joules of work is done in raising a 180 g apple, how far is it lifted?
1.1 m
The piston of an energy has a radius of 5.5 x 10^-2 m and is displaced a distance of 0.28 m when the pressure within the cylinder is 3.5 x 10^5 Pa. If the efficiency of the energy is 0.44, how much work must the engine give up as heat to the low-temperature reservoir?
1.1 x 10^3 J
A wave with a frequency of 20 Hz and a wavelength of 0.5 meters has a speed of
10 meters per second.
An automobile sped along a straight road for 30 minutes. For the first 10 minutes, it traveled at 90 km/hr. For the last 20 minutes, it traveled at 120 km/hr. At the end of 30 minutes, it was 55 km away from its initial point. What was the average velocity of the automobile?
110 km/hr
A 3.49 x 10^-3 kg lead bullet travels at a speed of 2.52 x 10^2 m/s and hits a wooden post. If half the total internal energy remains with the bullet, and it takes 1.30 x 10^2 J of energy to raise the temperature of a kilogram of lead by 1.00*C, what is the increase in temperature of the embedded bullet?
122° C
A periodic wave has a wavelength of 0.58 m and a speed of 14 m/s. What is the wave frequency?
24 Hz
Waves propagate along a stretched string at a speed of 6.9 m/s. The end of the string vibrates up and down once every 3.6 s. What is the wavelength of the the waves traveling along the string?
25 m
A construction worker pushes a wheelbarrow 5.0 m with a horizontal force of 50.0 N. How much work is done by the worker on the wheelbarrow?
250 J
A stunt man jumps from a bridge with a bungee cord attached. After bouncing up and down a couple of times, the man settles into a few oscillations of simple harmonic motion. If the man has a mass of 95 kg, and his period of oscillation is 12 s, what is the spring constant of the bungee cord?
26 N/m
A water tunnel has a circular cross section where the diameter diminishes from 3.6 m to 1.2 m. If the velocity of water is 3.0 m/s in the larger part of the tunnel, what is the velocity of water in the smaller part of the tunnel?
27 m/s
A jet engine develops 1.1 x 10^5 N of thrust to move an airplane forward at a speed of 9.3 x 10^2 km/h. What is the power output of the engine?
29 MW
An airplane climbs at a 30-degree angle from the horizontal at a velocity of 100 m/s. How fast does the airplane gain altitude?
50 m/s
A worker pushes a box with a horizontal force of 40.0 N over a level distance of 4.0 m. If a frictional force of 27 N acts on the box in a direction opposite to that of the worker, what net work is done on the box?
52 J
A dog walks 17 steps north and then walks 51 steps west to bury a bone. If the dog walks back to the starting point in a straight line, how many steps will the dog take?
54 steps
A cube of wood with a density of 0.780 g/cc is 10.0 cm on each side. When the cube is placed in water, what buoyant force acts on the wood? (nw = 1.00 g/cc)
7.65 N
The temperature of an oxygen tank is at 279 K, and the temperature of a nitrogen tank is 15°C. How much greater is the temperature of the nitrogen tank?
9 K
When a mechanical wave's amplitude is tripled, the energy the wave carries in a given time interval is increased by a factor of
9.
California sea lions can swim as fast as 40.0 km/h. Suppose a sea lion begins to chase a fish at this speed when the fish is 60.0 m away. The fish, of course, does not wait, and swims away at a speed 16.0 km/h. How long would it take the sea lion to catch the fish?
9.00 s
Convert 92 * 10^3 km to decimeters in scientific notation.
9.2 * 10^8 dm
A track star in the long jump goes into the jump at 12 m/s and launches herself at 20.0* above the horizontal. What is the magnitude of her horizontal displacement? (Assume no air resistance and that a(y) = -g = -9.81 m/s^2.)
9.2 m
What is the magnitude of the acceleration of an object in free fall near Earth's surface?
9.81 m/s^2
If Fnet = Fg, what is the magnitude and direction of the acceleration of the object? Assume that the object is on the Earth's surface.
9.81 m/s^2, downward
A balloon is inflated from a 0.005 m^3 volume to a 0.010 m^3 volume. The pressure stays the same at 1.8 x 10^5 Pa. How much work is done on the balloon?
900 J
Which of the following correctly reported measures was measured with a meter stick divided into millimeters?
932.6 mm
A sled weighing 1.0 x 10^2 N is held in place on a frictionless 20.0* slope by a rope attached to a stake at the top. The rope is parallel to the slope. What is the normal force of the slope acting on the sled?
94 N
A young mother pushes her baby in a stroller through the park. THe handle of the stroller is at 45 degrees and she pushes with a force of 55 N for a distance of 250 m. How much work is done?
9800 J
Which of the following statements is not correct?
A fluid has a definite shape.
If a force is exerted on an object, which statement is true?
A small force applied over a long time interval can produce a large change in the object's momentum.
Displacement is the same thing as distance traveled
False
A chunk of ice with a mass of 1 kg at 0 degrees C melts and absorbs 3.33 x 10^5 J of heat in the process. Which best describes what happened to this system?
Its entropy increased.
Which of the following does not change in a closed system? (KE = kinetic energy; PE = potential energy; U = internal energy)
KE + PE + U
As you may recall, momentum (p) is computed as the product of mass and velocity (mv). Using your knowledge of algebra, answer the following question: Which equation correctly defines kinetic energy in terms of momentum? (Recall that KE = 0.5mv2)
KE = 0.5pv
The SI unit for temperature is the
Kelvin
UNIT 3
LESSON 12
How are frequency and period related in simple harmonic motion?
They are inversely related.
Two areas within physics are mechanics and quantum mechanics. Distinguish between these two areas.
Mechanics studies the interactions of large objects, while quantum mechanics studies the behavior of subatomic (or very small) particles.
Which statement about models is not correct?
Models manipulate a single variable or factor in an experiment
Which of the following statements about the conservation of momentum is not correct?
Momentum is not conserved for a system of objects in a head-on collision.
If a very small particle at a high speed, such as a proton in a particle accelerator, collides with another particle, which of the following will definitely happen?
Momentum will be conserved.
Which of the following is NOT a unit of fluid pressure?
N/m
Which of the following statements is characteristic of the earlier days of thermodynamic research?
No machine is 100% efficient.
Which of the following best describes the relationship between two systems in thermal equilibrium?
No net energy is exchanged.
How does the theory of field forces explain how objects could exert forces on each other without touching?
Objects exert forces on each other when their fields interact.
Which of the following statements is true according to Pascal's principle?
Pressure in a fluid is the same throughout the fluid.
For an ideal fluid flowing through a horizontal pipe, Bernoulli's principle and the continuity equation state that the pressure within the pipe does which of the following? (Assume measurements are taken along the pipe in the direction of fluid flow.)
Pressure increases as the pipe diameter increases.
Which of the following is true during a phase change?
Temperature remains constant.
Why is the net force on a submerged object called its apparent weight?
The buoyant force on the object pushes upward on the object so that the net force is less than the weight of the object. The object thus appears to weigh less within the fluid.
Which of the following statements about completely submerged objects resting on the ocean bottom is correct?
The apparent weight of the object depends on the object's density.
Using Newton's Law of Universal Gravitation, one student figured the gravitational mass of the Earth. Using its centripetal acceleration, another student figured the inertial mass of the Earth. If the calculations were correct, how would the two masses compare?
The gravitational mass equals the inertial mass.
If the magnitude of a vector component equals zero, what is the magnitude of the other vector component?
The magnitude of the other component vector is the magnitude of the vector.
Why do calculators often exaggerate the precision of a final result?
They return answers with as many digits as the display can show.
Two pinewood derby (wooden) cars are racing down a frictionless ramp. Their wheels are also frictionless. One weighs 5.0 ounces; the other weighs 4.5 ounces. Neglecting air resistance, which will reach the end of the ramp first?
They will reach at the same time.
Which would fall with greater acceleration in a vacuum-a leaf or a stone?
They would accelerate at the same rate.
An observer accurately measures the constant velocity of a car from her frame of reference. Another observer measures the constant velocity of the car from his frame of reference. If the two frames of reference are at rest with respect to each other, how will the velocity measurements compare?
The velocity measurements will be the same.
What does the wattage of a light bulb indicate?
The wattage tells the rate at which energy is converted by the bulb.
Two waves traveling in opposite directions on a rope meet and undergo complete destructive interference. Which of the following best describes the waves a moment after the waves meet and coincide?
The waves continue unchanged.
If you cannot exert enough force to loosen a bolt with a wrench, which of the following should you do?
Use a wrench with a longer handle.
Although you may see multiple waves from the entry and the splash, a ripple in a calm pond caused by a rock falling into the pond, would be considered
a pulse wave.
The temperatures of the air in a rising balloon are recorded in Celsius degrees and transmitted as follows: 27.0, 25.5, 24.7, 22.8, 32.4. What is the best way to respond to the measurements, if you are the scientist in charge of the project?
Verify them, particularly the last one, which does not fit into the pattern of the others, by checking the equipment and the communication system.
How is the conservation of a system's internal energy mathematically expressed for an isovolumetric process?
W = 0 for an isovolumetric process, so deltaU = Q.
Harmonic motion is distinguished by
a restoring force that gets bigger the farther the object is from the resting point.
Which of the following is NOT a modification of an inclined plane?
a lever
A free-body diagram of a ball falling in the presence of air resistance would show
a downward arrow to represent the force due to gravity and an upward arrow to represent the force of air resistance.
What kind of simple machine are you using if you pry a nail from a board with the back of a hammer?
a lever
The ratio of the change in an object's velocity to the time required for the change to occur describes what quantity?
acceleration
A mass attached to a spring vibrates back and forth. At maximum displacement, the spring force and the
acceleration reach a maximum.
To obtain the motion of an object measured in one frame of reference, in its relation to another frame of reference, you must
add the motion of the object to the motion of the frame of reference
When two waves occupy the same place at the same time, if they are of the same sign, they _____________their magnitudes in ___________ interference.
add; constructive
Which thermodynamic process takes place when work is done on or by the system but no energy is transferred to or from the system as heat?
adiabatic
What causes a projectile not to follow a parabolic path?
air resistance
To say that no collision is instantaneous is the same as saying
all changes in momentum take time.
The strength of the vibrations in a sound wave corresponds to the ______ of a sine wave generated by the sound vibrations.
amplitude
For a mass hanging from a spring, the maximum displacement the spring is stretched or compressed from its equilibrium position is the system's
amplitude.
The angle between the string of a pendulum at its equilibrium position and at its maximum displacement is the pendulum's
amplitude.
Which of the following is a way of indicating vector direction?
an angle off of vertical
Vectors
can be added many at a time
Which of the following will NOT cause a floating raft to sink?
decrease its density
When a mechanical wave's amplitude is reduced by half, the energy the wave carries in a given time interval is
decreased to one-fourth.
A 75 kg person walking around a corner bumped into an 80 kg person who was running around the same corner. The momentum of the 80 kg person
decreased.
A 20 kg shopping cart moving at a velocity of 0.5 m/s collides with a store wall and stops. The momentum of the shopping cart
decreases.
Two mechanical waves meet and coincide. One wave has a positive displacement from the equilibrium position, and the other wave has a negative displacement. What kind of interference occurs?
destructive
Which of the following is a way to determine the net external force?
determine the vector sum of all external forces acting upon the object
Suppose that two sound waves passing through the same medium have different wavelengths. Which of the following is most likely to be the reason for the differing wavelengths?
differences in frequency
Tides are caused by
differences in the gravitational force of the moon at different points on Earth.
Two cars of equal mass, moving at different speeds along a road, will have
different kinetic energies.
In uniform circular motion, the ______ of motion is constantly changing.
direction
The quality that velocity has, that speed does not, is
direction
Standing waves are formed when two waves have the same frequency, amplitude, and wavelength, but opposite
directions.
Vibration of an object about an equilibrium point is called simple harmonic motion when the restoring force is proportional to
displacement.
Slope is defined as "rise over run." In a displacement-time graph, the rise equals the change in ______ and the run represents the change in _____.
displacement; time
Which of the following is NOT a vector quantity?
distance
The equation for calculating average speed is
distance traveled/time of travel
The node of a standing wave
does not move.
What quantity measures the work done by a machine relative to the work done on a machine?
efficiency
What term is used to describe the measure of useful energy taken out of a process relative to the total energy put into the process?
efficiency
The potential energy of mechanical energy can be either
elastic or gravitational.
A mass-spring system can oscillate with simple harmonic motion because a compressed or stretched spring has which kind of energy?
elastic potential
Air resistance acts in the direction ________ an object's motion.
opposite to
When a fluid is heated, the heat spreads throughout the fluid chiefly by the process of _________.
convection
The newton is the SI unit of what physical quantity?
force
What causes a moving object to change direction?
force
When freezing home made ice cream, a salt, water, and ice mixture is used. The coldest temperature that can be obtained with this mixture is approximately -4.5 degrees F. What is this temperature on the Celsius and Kelvin scales.
-20.3 C; 252.8 K
Which of the following does NOT resist changing conditions?
force
An ideal gas system undergoes an adiabatic process in which it expands and does 20 J of work on its environment. What is the change in the system's internal energy?
-20 J
Which of the following is the cause of an acceleration?
force
An ideal gas is maintained at a constant pressure of 9.8 x 10^4 N/m^2 while its volume decreases by 0.38 m^3. What work is done by the system on its environment?
-3.7 x 10^4 J
What temperature has the same numerical value on both the Fahrenheit and the Celsius scales?
-40.0°
A ball with a momentum of 4.0 kg.m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum?
-8.0 kg.m/s
A child moving at constant velocity carries a 2 N ice-cream cone 1 m across a level surface. What is the net work done on the ice-cream cone?
0 J
A passenger at the rear of a train traveling at 15 m/s relative to Earth throws a baseball with a speed of 15 m/s in the direction opposite the motion of the train. What is the velocity of the baseball relative to Earth as it leaves the thrower's hand?
0 m/s
A 0.75 kg ball moving at 3.9 m/s to the right collides head-on with an identical ball moving at 3.9 m/s to the lift in a perfectly inelastic collision. Find the common velocity of the balls and the decrease in kinetic energy during the collision.
0.0 m/s; -11.4 J
A lightning bug flies at a velocity of 0.15 m/s due east toward another lightning bug seen off in the distance. A light easterly breeze blows on the bug at a velocity of 0.15 m/s. What is the resultant velocity of the lightning bug?
0.00 m/s
A gas exerts a pressure of 6.0 x 10^5 Pa on a piston in a cylinder of cross-sectional area of 0.075 m^2 . If the gas moves the piston 0.025 m, find the change in volume of the cylinder and the work done by the gas.
0.0019 m^3 ; 1100 J
Many dolphins can produce ultrasounds, sounds above the range of human hearing. They may use these sounds to echolocate. The highest frequency of sound that can be produced by bottlenose dolphins is around 1.5 x 10^5 Hz. The speed of sound in sea water is 1560 m/s. What is the wavelength of the sound produced?
0.01 m
After the lake has frozen solid, an ice fisherman pulls his house out to his favorite fishing spot. It is pulled by a rope attached to a hook on the side of the house. The rope makes an angle of 25.0 degrees with the horizontal and exerts a force of 50.0 N. The house has a mass of 405 kg. The coefficient of kinetic friction between the wooden house and the ice is 0.0100. What is the acceleration of the house?
0.014 m/s/s
A 0.29 kg aluminum plate slides down a 16 m long surface that is inclined at a 30.0* angle to the horizontal. The force of kinetic friction exactly balances the component of gravity down the plane so that the plate, once started, glides down at a constant velocity. If 82.2 percent of the mechanical energy of the system is absorbed by the aluminum, and it takes 9.00 x 10^2 J to raise the temperature of a kilogram of aluminum 1.00*C, what is the temperature increase of the plate when it is at the bottom of the incline? (g = 9.81 m/s^2)
0.072°C
A 0.12 kg object makes an elastic head-on collision with a 0.18 kg stationary object. The final velocity of the 0.12 kg object after the collision is 0.048 m/s in the direction opposite its initial movement. The final velocity of the 0.18 kg object after the collision is 0.19 m/s in the same direction as the object which strikes it. What was the initial velocity of the 0.12 kg object?
0.23 m/s forward
A girl rides a Ferris wheel with a radius of 25 meters. Her tangential speed (what speed she would go at if she got out of the Ferris wheel car) is 2.5 m/s. How large is the centripetal acceleration that keeps her in the circular motion?
0.25 m/s/s
A turbine exhausts 62 500 J of energy as heat when it puts out 22 100 J of net work. What is the efficiency of the turbine?
0.261
A row of five 1.2 N wooden blocks is being pushed across a tabletop at a constant speed by a toy tractor that exerts a force of 1.7 N on the row. What is the coefficient of kinetic friction between the wooden blocks and the tabletop?
0.28
A 0.20 kg arrow traveling at 10. m/s, strikes a stationary hanging target, which has a mass of 3.0 kg. How fast will the arrow and target swing immediately after the collision?
0.31 m/s
An Olympic skier moving at 19.0 m/s down a 26.0* slope encounters a region of wet snow and slides 136 m before coming to a halt. What is the coefficient of friction between the skis and the snow? (g = 9.81 m/s^2)
0.337
A crate is carried in a pickup truck traveling horizontally at 15.0 m/s. The truck applies the brakes for a distance of 28.7 m while stopping with uniform acceleration. What is the coefficient of static friction between the crate and the truck bed if the crate does not slide?
0.400
How high would a 0.5-kg pendulum have to swing in order to have a potential energy of 2.3 J? (Assume a gravitational acceleration of 9.8 m/s/s.)
0.47 m
In a 30-60-90 degree right triangle, the side opposite the 30 degree angle is half the length of the hypotenuse. Therefore, the sine of 30 degrees is
0.5
A stroller walks the first half of a straight 1.4 km trail at a steady pace of 1.7 m/s, east. He walks the second half at a constant stride of 0.37 m/s, east. What is his average velocity along the trail?
0.61 m/s, east
An engine absorbs 2310 J as heat from a hot reservoir and gives off 830 J as heat to a cold reservoir during each cycle. What is the efficiency of the engine?
0.64
Vibration of a certain frequency produces a standing wave on a stretched string that is 1.6 m long. The standing wave has 7 nodes and 5 antinodes. What is the wavelength of the wave that produces this standing wave?
0.64 m
A juggler is strolling a moving walkway while tossing a ball vertically upward to a height of 3.60 m. The juggler strolls at a constant velocity of 1.20 m/s with respect to the walkway, which moves at a constant velocity of 0.50 m/s with respect to the ground. An observer on the ground passes the juggler and notices that the path of the ball is a parabola with a maximum width of 1.80 m. What is the velocity of the observer with respect to the ground? (Assume no air resistance and that a(y) = -g = -9.81 m/s^2.)
0.649 m/s opposite the direction of the moving sidewalk
Four liquids with densities of 1.260 g/cm^3, 0.690 g/cc, 0.970 g/cc, and 0.870 g/cc are poured into a container. The liquids form separate layers, with one liquid floating above another. What are the densities of the liquids, in order from the liquid at the top to the one at the bottom?
0.690 g/cc, 0.870 g/cc, 0.970 g/cc, 1.260 g/cc
Find the magnitude of the torque produced by a 3.0 N force applied to a door at a perpendicular distance of 0.25 m from the hinge.
0.75 N-m
A stagehand starts sliding a large piece of stage scenery originally at rest by pulling it horizontally with a force of 177 N. What is the coefficient of static friction between the stage floor and the 230 N piece of scenery?
0.77
In a 45-45-90 degree right triangle, the sides of the triangle are equal. The tangent, therefore, of a 45 degree angle is
1
Convert 1 micrometer to meters using scientific notation.
1 * 10^-6
What is the increase in the internal energy per kilogram of water at the bottom of a 115 m waterfall, assuming that all of the initial potential energy is transferred as heat to the water? (g = 9.81 m/s^2)
1.13 x 10^3 J/kg
A slice of bread contains about 4.19 x 10^5 J of energy. If the specific heat capacity of a person is 4.19 x 10^3 J/kgC, by how many degrees Celsius would the temperature of a 70.0 kg person increase if all the energy in the bread were converted to heat?
1.43°C
A remote control model boat is crossing a creek with a velocity of 8.0 km/hr due north with respect to the water. The creek has a uniform velocity of 7.0 km/hr due east. Determine the boat's velocity with respect to an observer on shore.
10.6 km/hr 41 degrees east of north
A remote control model boat is crossing a creek with a velocity of 8.0 km/hr due north with respect to the water. The creek has a uniform velocity of 7.0 km/hr due east. What is the boat's velocity with respect to an observer on shore?
10.6 km/hr at 41 degrees east of north
A one-kg sample of Substance X is heated with 1000 J of heat and the temperature rises in the substance 10 degrees C. What is its specific heat capacity?
100 J/kg-K
What is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s?
108 J
Estimate the order of magnitude of the length of a football field.
10^2 m
The sun is composed mostly of hydrogen. The mass of the sun is 2.0 * 10^30 kg, and the mass of a hydrogen atom is 1.67 * 10^-27 kg. Estimate the number of atoms in the sun.
10^57
A certain string that is 1.0 m long vibrates with a standing wave that has a wavelength of 2.0 m. How many nodes and antinodes will appear on the vibrating string?
2 nodes (the ends) and 1 antinode (the center)
A rope attached to an engine pulls a 240 N crate up an 14.7* ramp at a constant speed. The coefficient of kinetic friction for the surfaces of the crate and ramp is 0.32. What is the magnitude of the force that the rope exerts on the crate parallel to the ramp? (g = 9.81 m/s^2)
135 N
A certain pendulum swings through an angle of 30° between positions of maximum displacement. What is the amplitude of this pendulum?
15 degrees
A nail is driven into a board with an initial kinetic energy of 150 J. If the potential energy before and after the event is the same, what is the change in the internal energy of the board and nail?
150 J
An iron bar is used to lift a slab of cement. The force applied to lift the slab is 4.0 x 10^2 N. If the slab weighs 6400 N, what is the mechanical advantage of the bar?
16
A 2200 kg pickup truck moves at a speed of 18 m/s to the east. The pickup collides with a tree, coming to rest in a time of 0.25 s. What is the magnitude of the force exerted on the truck during the collision?
160 000 N
A soap-box derby race car sits on the starting ramp. The ramp is elevated at an angle of 8.5 degrees. The angle between the gravity vector and the ramp surface is a . The force of gravity on the car is 1225 N. The normal force of the track on the car is 1210 N. The frictional force of the track on the car is 15.2 N. What is the net force on the car?
166 N
A car of mass 2050 kg travels initially at 22.4 m/s to the east. The car slows uniformly until it is at rest. If the force acting on the car is 2350 N to the west, what is the time it takes for the car to stop, and what is the distance it travels while stopping?
19.5 s; 218 m to the east
A sports car traveling at 24.7 m/s slows at a constant rate to a stop in 16.00 s. What is the displacement of the sports car in this time interval?
198 m
The angle that provides the most torque is _______ to the lever arm.
perpendicular to
An airplane with a mass of 1.20 x 10^4 kg tows a glider with a mass of 0.60 x 10^4 kg. If the airplane propellers provide a net forward thrust of 3.60 x 10^4 N, what is the acceleration of the glider? (Disregard friction.)
2.00 m/s^2
The gauge pressure for the air in a balloon equals 1.01 x 10^5 Pa. If atmospheric pressure is equal to 1.01 x 10^5 Pa, what is the absolute pressure of the air inside the balloon?
2.02 x 10^5 Pa
Find the distance between a bowling ball of mass 6.00 kg and a marble of mass 0.025 kg if the magnitude of the gravitational attraction is 2.25 x 10^-12 N. The value of G is 6.673 x 10^-11 N-m^2 /kg^2.
2.1 m
Two perpendicular forces, one of 45.0 N directed upward and the other of 60.0 N directed to the right, act simultaneously on an object with a mass of 35.0 kg. What is the magnitude of the resultant acceleration of the object?
2.14 m/s^2
Which of the following wavelengths would produce standing waves on a string approximately 3.5 m long?
2.33 m
A 29% efficient heat engine has 3.35 x 10^7 J of energy added in the form of fuel. How much energy is lost to the surroundings?
2.4 x 10^7 J
Each of the four tires on an automobile has an area of 0.026 m^2 in contact with the ground. The weight of the automobiles is 2.6 x 10^4 N. What is the pressure in the tires?
2.5 x 10^5 Pa
What is the average power output of a weightlifter who can lift 260 kg to a height of 1.9 m in 1.8 s?
2.7 kW
An airplane flying at 180 km/h due west moves into a region where the wind is blowing at 60 km/h due east. If the plane's original vector velocity is Vplane, what is the expression for the plane's resulting velocity in terms of Vplane?
2/3 Vplane
An ideal gas system undergoes an isovolumetric process in which 20 J of energy is added as heat to the gas. What is the change in the system's internal energy?
20 J
A substance registers a temperature change from 20°C to 40°C. To what incremental temperature change does this correspond?
20 K
A 0.2 kg baseball is pitched with a velocity of 40 m/s and is then batted to the pitcher with a velocity of 60 m/s. What is the magnitude of change in the ball's momentum?
20 kg.m/s
A continuously-flowing pipe has an opening area of 100 cm^2 . The water goes in at 10 m/s. The end of the pipe is only 50 cm^2 in cross-sectional area. What is the speed of the water when it exits the pipe?
20 m/s
How much elastic potential energy is stored in a bungee cord with a spring constant of 10.0 N/m when the cord is stretched 2.00 m?
20.0 J
A horizontal force of 200 N is applied to move a 55 kg television set across a 10 m level surface. What is the work done by the 200 N force on the television set?
2000 J
A hang glider flies north with a velocity of 18 km/hr relative to the wind. The wind has a uniform velocity of 12 km/hr due west. Determine the hang glider's velocity with respect to an observer on the ground.
21 km/hr 34 degrees west of north.
Chante rider her motorcycle around a curve in the road. The section of curve can be approximated by a circle of radius 305 m. If she has a centripetal acceleration of 1.66 m/s/s, what is Chante's tangential speed?
22.5 m/s
Tarzan is hanging from the end of a horizontal branch, 1.80 m from the trunk of the tree. His friend Jane is standing on the same branch at a distance of 0.95 m from the trunk. What is the net torque on the branch at the trunk? Jane weighs 490 N, and Tarzan weighs 1030 N.
2320 N-m
A heavy bank-vault door is opened by the application of a force of 3.0 x 10^2 N directed perpendicular to the plane of the door at a distance of 0.80 m from the hinges. What is the torque?
240 N.m
A turbine takes in 67 500 J of energy as heat and does 18 100 J of work during each cycle. Calculate the efficiency of the turbine. Express it as a percentage.
26.8 %
A hiker travels south along a straight path for 1.2 h with an average speed of 4.1 km/h and then travels north for 1.7 h with an average speed of 4.7 km/h. What is the hiker's displacement for the total trip?
3.1 km, north
Radio waves from an FM station have a frequency of 95.9 MHz. If the waves travel with a speed of 3.00 x 10^8 m/s, what is the wavelength?
3.13 m
In the U.S., refrigerators are kept at a temperature range of 38 to 42 degrees F. What is this range in Celsius?
3.4 to 5.6 degrees C.
A hammer drives a nail at a speed of 0.42 m/s into a piece of wood. The wood does not move during this action. If the mass of the nail is 78.2 g and half of its mechanical energy is transferred to the wood as heat, how much does the internal energy of the wood change?
3.4 x 10^-3 J
A pendulum is suspended from the ceiling nearly to the floor. You observe that the pendulum swings through a complete cycle in a time of 3.75 seconds. What is the height of the room. (g = 9.81 m/s/s)
3.49 m
The fastest snake on Earth is the black mamba, which can move over a short distance at 18.0 km/h. Suppose a mamba moves at this speed toward a rat sitting 12.0 m away. The rat immediately begins to run away at 33.3 percent of the mamba's speed. If the rat jumps into a hole just before the mamba can catch it, determine the length of time that the chase lasts
3.60 sec
A trapeze artist on a rope is momentarily held to one side by a partner on a platform. The rope makes an angle of 26.0∑ with the vertical. In such a condition of static equilibrium, what is the magnitude of the horizontal force being applied by the partner? The weight of the artist is 7.61 ∑ 10^2 N.
3.71 ∑ 10^2 N
A waitperson pushes the bottom of a glass tumbler full of water across a tabletop at a constant speed. The tumblers and its contents have a mass of 0.86 kg, and the coefficient of kinetic friction for the surfaces in contact is 0.46. What force does the waitperson exert on the glass? (g = 9.81 m/s^2)
3.9 N
If a 30 kg mass going 20 m/s collides in a linear direction with a 20 kg mass at rest and stops, and momentum is conserved, how fast will the 20 kg mass go after the collision?
30 m/s
If the torque required to loosen a nut on a wheel has a magnitude of 40.0 N.m and the force exerted by a mechanic is 133 N, how far from the nut must the mechanic apply the force?
30.1 cm
The body temperature of a certain human being is 98.27?F. What does this temperature equal in kelvins?
309.97 K
A musical tone sounded on a piano has a frequency of 215.1 Hz and a wavelength of 1.47 m. What is the speed of the sound wave?
316 m/s
An Olympic curler delivers a stone with an initial speed of 4.4 m/s. The stone has a mass of 20.0 kg. The coefficient of friction between the stone and the ice is 0.030. Assume the acceleration of gravity is 9.81 m/s/s. What is the distance that the stone will travel before it comes to a complete stop?
32 m
A lever with its fulcrum between the force and the weight is used to lift a 200 N weight 0.5 meters. The total length of the lever is 4 meters. The fulcrum is placed 1.0 meters from the end of the lever on the weight side. How much force must be applied to lift the weight, and how long a distance will the lever go down.
33 N for 3 meters
What is the efficiency of a machine that requires 1.00 x 10^2 J of input energy to do 35 J of work?
35%
A clay ball with a mass of 0.48 kg has an initial speed of 4.08 m/s. It strikes a 3.04 kg clay ball at rest, and the two balls stick together and remain stationary. What is the decrease in kinetic energy of the 0.48 kg ball?
4.0 J
The gravitational force between two masses is 36 N. What is the gravitational force if the distance between them is tripled? (G = = 6.673 x 10^-11 N.m^2/kg^2)
4.0 N
An empty train car of mass 12000 kg moves at 12 m/s to the east. The car collides with a loaded train car initially at rest. If the mass of the loaded train car is 24000 kg, find the final velocity of the cars, as they stick together after the collision.
4.0 m/s to the east
A 15 g sample was taken from the solid to the gaseous state. The temperature did not change as the sample melted, until 7.10 kJ more had been added, at which time the temperature began to rise again. What is the latent heat of fusion for the substance? (Express it as J/kg)
4.7 x 10^5 J/kg
Two small masses that are 10.0 cm apart attract each other with a force of 10.0 N. When they are 5.0 cm apart, these masses will attract each other with what force? (G = 6.673 x 10^-11 N.m^2/kg^2)
40.0 N
A cylinder has a radius of 0.082 m. How much work is done by a gas in the cylinder if the gas exerts a constant pressure of 7.5 x 10^5 Pa on the piston, moving it a distance of 0.026 m?
410 J
A falling stone with a mass of 0.398 kg strikes the ground. Assuming that the stone is initially at rest when it begins falling, how high must the stone be above the ground for the internal energy of the stone and ground to increase by 1670 J? (g = 9.81 m/s^2)
428 m
A crate with a mass of 76 kg is hung from a spring. The displacement of the spring is -0.17 m. What is the spring constant of the spring? (The acceleration of gravity is 9.81 m/s/s.)
4400 N/m
A superhero drops from a hovering helicopter to catch a bad guy on a motorcycle. The superhero hits the bad guy falling at a velocity of 30. m/s after a 3.1 second drop. How far did the superhero fall?
46 m
A girl sits on the edge of a playground merry-go-round of radius 2.50 m. Her tangential speed is 3.1 m/s. If the force that maintains the girl's circular motion is 180 N, what is the girl's mass?
47 kg
A shopping cart is given an initial velocity of 2.0 m/s and undergoes a constant acceleration of 2.0 m/s^2. What is the magnitude of the cart's displacement after the first 6.0 s of its motion?
48 m
Turtles are fairly slow on the ground, but they are very good swimmers, as indicated by the reported speed of 9.0 m/s for the leatherback turtle. Suppose a leatherback turtle swims across a river at 9.0 m/s relative to the water. If the current in the river is 3.0 m/s and it moves at a right angle to the turtle's motion, what is the turtle's displacement with respect to the river's bank after 1.0 min?
570 m 18 degrees from perpendicular
A sail is set at a 45.0 degree angle to the wind. The force of the wind over the area of the sail is 5100 N. The wind moves the boat 2.0 kilometers. How much work is done on the boat?
7.2 x 10 6 joules
A duck waddles 2.3 m east and 7.0 m north. What are the magnitude and direction of the duck's displacement with respect to its original position?
7.3 m at 72° north of east
Bats chirp at high frequencies that humans cannot hear. They use the echoes to detect objects, such as insects, that are as small as one wavelength. If a bat emits a chirp at a frequency of 45.4 kHz and the speed of sound waves in air is 340 m/s, what is the size in millimeters of the smallest insect that the bat can detect?
7.5 mm
In a game of tug-of-war, a rope is pulled by a force of 182 N to the right and by a force of 108 N to the left. What is the magnitude and direction of the net horizontal force on the rope?
74 N, to the right
A 1.71 x 10^3 kg sports car accelerates from rest to 25.8 m/s to in 7.41 s. What is the average power output of the automobile engine?
76.8 kW
A biker travels at an average speed of 11.1 m/s along a 8.9 * 10^3 m straight segment of a bike path. How much time does the biker take to travel this segment?
8.0 * 10^2 s
A container of gas is at a pressure of 1.7 x 10^5 Pa and a volume of 4.9 m^3. How much work is done by the gas if it expands at constant pressure to twice its initial volume?
8.3 x 10^5 J
Convert 8.66 * 10^-9 m to millimeters using scientific notation.
8.66 * 10^-9 mm
How fast must you toss a ball upwards to get it to travel 4.0 meters upward before it stops and falls to the ground?
8.9 m/s
A hot 0.200 kg brass cube is dropped into an insulated container that has 0.150 kg of water. The water is initially at a temperature of 12.0 degrees C. The final temperature of the water and brass is 20.0 degrees C. If the specific heat capacity of brass is 380.0 J/kg.C, and the specific heat capacity of water is 4186 J/kg.C, what is the initial temperature of the brass cube?
86 degrees C
Which of the following hypotheses on why the sky is blue is testable?
A diffuse light environment backed by a black background looks blue.
Which of the following terms represents the gravitational potential energy of a fluid?
pgh
A child pulls a toy across the floor. Is the work done on the toy positive, negative, or zero?
positive
For a mechanical wave, the energy it carries is proportional to
the square of the amplitude.
The flow of air around the airplane wing reduces the pressure of the air. The wing is shaped so that air flows more rapidly over the wing than under it, and therefore causes the pressure above the wing to be lower than the pressure below it. The greater pressure under the wing raises the wing, causing the airplane to lift. This is an application of
Bernoulli's principle.
Two pulses of equal positive amplitude travel along a rope toward a fixed boundary. The first pulse is reflected and returns along the rope. When the two pulses meet and coincide, what kind of interference will occur?
Complete destructive interference
Kepler developed his laws of planetary motion as he tried to reconcile
Copernican theory with Tycho Brahe's data.
What accounts for an increase in the temperature of a gas that is kept at constant volume?
Energy has been added as heat to the gas.
If there is no temperature difference between a substance and its surroundings, what has occurred on the microscopic level?
Energy has been transferred from higher-energy particles to lower-energy particles.
"Heat" and "cold" do not flow between objects. ________changes the temperature of the objects.
Energy transferred between objects.
Which of the following is an algebraic statement of Pascal's principle?
F 2 = F 1 (A 2 /A 1 )
How is the relationship between period and frequency represented as an equation?
F = 1/T
The same amount of energy will raise all substances the same increment of temperature.
False
In the experiment, paddles were turned by the falling weights. How did they heat the fluid?
Friction generated by the movement gave internal energy to the fluid.
Which of the following statements applies to the motion of a ball rising and then falling in free fall? I. The ball has constant acceleration as it moves upward. II. The ball has constant acceleration at the top of its path. III. The ball has constant acceleration as it moves downward.
I, II, and III
A thermodynamic process occurs, and the entropy of a system decreases. What can be concluded about the entropy change of the environment?
It increases.
What happens to the internal energy of an ideal gas when it is heated from 0°C to 4°C?
It increases.
Which of the following statements does NOT describe the direction of the normal force?
It is always directed exactly opposite to gravity.
Imagine you could observe the individual atoms that make up a piece of matter and that you observe the motion of the atoms becoming more orderly. What can you assume about the system?
Its entropy is decreasing.
Which of the following is not a unit of power?
J
UNIT 3
LESSON 15
UNIT 4
LESSON 16
UNIT 4
LESSON 17
UNIT 4
LESSON 18
UNIT 5
LESSON 21
UNIT 6
LESSON 26
UNIT 1
LESSON 3
Why is the sound produced by a collision evidence that the collision is not perfectly elastic?
Producing sound requires energy.
Which motor performs more work in the same amount of time-a 10 kW motor or a 20 kW motor? How much more work can it do?
The 20 kW motor does twice as much work in the same amount of time.
What feature of a wave increases when the source of vibration increases in energy?
The amplitude increases.
A car as it moves along a level highway with the following forces acting upon it. Gravity exerts a downward force on the car that is balanced by the normal force of the road acting upward on the car. The car's forward motion is opposed by the friction between the road and the tires and by the resistance of the air. The sum of these opposing forces is balanced by an equal and opposite force exerted by the engine and applied to the tires, where the road exerts a reaction force that is directed forward. Describe the motion of the car.
The car is moving at a constant speed in a straight line.
A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike.
The child has a greater momentum than the bike.
How does the coefficient of static friction for two surfaces in contact compare to the coefficient of kinetic friction for the same two surfaces?
The coefficient of static friction is larger than the coefficient of kinetic friction for the same two surfaces in contact
Why does an astronaut weigh less on the moon than on Earth?
The gravitational field strength is less on the moon's surface than on Earth's surface.
If energy is transferred from a table to a block of ice moving across the table, which of the following statements is true?
The ice is cooler than the table.
Negative work is done on a moving object. How does the kinetic energy of the object change?
The kinetic energy will decrease.
A leaf falls from a tree and lands on the sidewalk. Identify an action-reaction pair in this situation.
The leaf exerts a force on the sidewalk; the sidewalk exerts a force on the leaf.
If unexpected results are obtained and confirmed through repeated experiments, why must a model or hypothesis be abandoned or revised?
The model or hypothesis is unable to make reliable predictions.
A buoyant force acts in the opposite direction of gravity. Therefore, which of the following is true of an object completely submerged in water?
The net force on the object is smaller than the weight of the object.
Which of the following occurs to a person standing near the edge of a railroad track when a high-speed train passes?
The person tends to be pulled toward the train.
A student sends a pulse traveling on a taut rope with one end attached to a post. What will the student observe?
The pulse will be reflected and inverted if the rope is fixed to the post.
One end of a rope is tied loosely to a post so that the end is free to flop up and down. Suppose you send a pulse along this rope from its opposite end. What would you expect to happen when the pulse reaches the post?
The pulse would be reflected but not inverted.
Two pulses of equal but opposite amplitudes meet on a rope. What will the rope look like at the instant when the two pulses coincide completely?
The rope will appear straight and flat (or very nearly flat).
Technology has made the SI standards more consistent. Which of the following is an original standard, not the current one?
The second is defined as 0.000011574 times the length of an average solar day.
Two springs have spring constants of 33 and 55, respectively. What can be said about how the springs act with the same mass?
The spring with a constant of 33 will stretch farther than the spring with a constant of 55.
When a falling object reaches terminal speed (where the acceleration on the object is zero), what is the relationship between F(R), the force of air resistance on the object, and F(g)?
The two forces are equal in magnitude and opposite in direction.
The spur-wing goose is one of the fastest birds in the world when it comes to level flying: it can reach a speed of 90.0 km/h. Suppose two spur-wing geese are separated by an unknown distance and start flying toward each other at their maximum speeds. The geese pass each other 40.0 s later. Calculate the initial distance between the geese.
The two geese are initially 2.00 km apart.
In which units is the coefficient of friction expressed?
There are no units for the coefficient of friction.
On a frictionless surface, a puck hits another puck of equal mass. The pucks hit at an angle, and the first puck bounces away at a 30 degree angle from its original line. Which of the following statements are true about the collision?
Total momentum of the two pucks before the collision will remain unchanged after the collision.
One can add two or more vectors algebraically by adding their x and y components and calculating the angle.
True
The goal of the steps of the scientific method is to draw conclusions.
True
Which of the following is an action-reaction pair?
When a baseball player catches a ball, the ball exerts force on the mitt, and the mitt exerts force on the ball.
Which of the following forces arises from direct physical contact between two objects?
contact force
Which of the following is a valid way to determine the spring constant, k ?
With a position of known potential energy, measure the distance away from relaxed, and calculate.
Which of the following is a result of an energy transfer?
Work is done.
Which of the following has the greatest power output?
a crane that lifts a 2.5 x 10^4 N beam at a speed of 1.2 m/s
Which of the following is a thermodynamic process in which a system returns to the same conditions under which it started?
a cyclic process
As fluids, the major difference between gases and liquids, is that liquids have
a definite volume.
Motion calculations are simplified by measuring motion in relation to
a fixed frame of reference
To move a bicycle forward, the rider must apply __________ to the pedals.
a force
Which of the following is a set of particles or interacting components to which energy is added or from which energy is removed?
a system
Which of the following has the greatest momentum?
a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s
Gravitational potential energy is always measured in relation to
a zero level.
A free-body diagram includes
all the forces acting upon an object.
It is difficult to build a campfire with damp wood because
all the heat goes into evaporating the water, rather than combusting the wood.
The reaction force of an action-reaction pair
always happens at the same time as the action.
A vase's gravity pushing down on a table is accompanied by the normal force of the table pushing up on the vase. Such a pair is called
an action-reaction pair.
Which of the following is a good example of a screw that is used to lift large weights a small distance by applying a small force over a large distance?
an automobile jack
An object decelerating in a positive direction will have the same sign as
an object accelerating in a negative direction
The flow of heat is always from _______ to ______.
an object of higher temperature; an object of lower temperature
Buoyancy is
an upward force, opposed to gravity.
Which of the seven skills outlined in the scientific method determines what conclusion a research projects comes up with?
analyzing results
Two mechanical waves can occupy the same space at the same time because waves
are displacements of matter.
If you want to open a swinging door with the least amount of force, where should you push on the door?
as far from the hinges as possible
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
at the top of its path
The reason for installing expansion joints in concrete and metal edifices is to
avoid buckling by allowing moderate thermal expansion.
Why cannot vectors be added simply by adding the magnitudes of the vectors?
because the direction is important also
If a nonzero net force is acting on an object, then the object is definitely
being accelerated.
Because of air resistance, a golfer should hit a shot whose projectile motion alone would make it land____________.
beyond the hole
One good use of the impulse-momentum theorem is to
calculate stopping time and distance.
Newton's law of universal gravitation
can be used to derive Kepler's third law of planetary motion.
Because it pulls to the center of the Earth, gravity on Earth causes a
centripetal acceleration.
What is the term for the net force directed toward the center of an object's circular path?
centripetal force
Which of the following is a good thermal insulator?
ceramic
Which of the following is found on the warm side of a refrigerator?
condenser
A student observes two pulses on a rope wave meet and temporarily form a wave with a greater amplitude than either of the two waves alone. The student has observed an example of ____________________ interference.
constructive
How is the conservation of a system's internal energy mathematically expressed for an isothermal process?
deltaU = 0 for an isothermal process, so Q - W = 0, or Q = W.
How is conservation of internal energy expressed for a system during an isovolumetric process?
deltaV = 0, so P deltaV = 0 and W = 0; therefore, deltaU = Q
What quantity describes the difference between an object's initial position and the object's final position?
displacement
Which is a vector quantity, distance or displacement?
displacement
The points of matter at the node of a standing wave
do not move.
One definition of energy is the ability to
do work.
The thermal expansion of hot gases in the cylinder of a 4-stroke combustion engine
does work against the piston.
According to the First Law of Thermodynamics, if the internal energy of a system is increased, then
either the heat of the system or the the work done by the system must increase, or both.
A stretched or compressed spring stores ____________________ potential energy.
elastic
Two billiard balls collide. Identify the type of collision.
elastic
Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision.
elastic
A pocket watch contains a long, spiral piece of metal which is coiled tightly as the watch is wound. What form of potential energy is involved in winding a pocket watch?
elastic potential energy
What form of energy is stored in any stretched or compressed object?
elastic potential energy
Which form of energy is involved in weighing fruit on a spring scale?
elastic potential energy
In physics, to say that energy is conserved means that
energy is not lost nor gained in the process.
Waves are one of the chief ways that
energy is transferred.
If you happened upon a very ordered array of sand crystals in the desert, you would have to conclude that
entropy had decreased there.
Two vectors that are parallel, with equal magnitude, are
equal
Distinguish between the displacement of a traveler who takes a train from New York to Boston and the displacement of a traveler who flies from Boston to New York. The magnitudes of the displacements are _____, but the displacements are in opposite directions. Therefore, one displacement is positive and the other displacement is _______.
equal, negative
The velocity of the bob on a swinging pendulum reaches a maximum when the bob is in the ____________________ position.
equilibrium
Graphs often permit scientists to make ____________________ for times when there is no data.
estimations (or predictions)
In the following sentence, is the everyday meaning or the scientific meaning of work intended? A student works on a term paper.
everyday meaning
In the following sentence, is the everyday meaning or the scientific meaning of work intended? A clerk works overtime on Saturdays.
everyday meaning
An object in orbit around the Earth ______________________________.
experiences constant centripetal acceleration
When there is no air resistance, objects of different masses dropped from rest
fall with equal accelerations and with equal displacements
Where should a force be applied on a lever arm to produce the most torque?
farthest from the axis of rotation
Objects that are falling toward Earth in free fall move
faster and faster
Which of the following forces exists between objects even in the absence of direct physical contact?
field force
How many significant figures are there in the number 17.250?
five
How many significant figures does 0.050 200 mg have?
five
If the buoyant force on an object is equal to the force of gravity, the object will
float.
A ____is a nonsolid state of matter in which the atoms or molecules are free to move past each other, as in a gas or liquid.
fluid
What factors affect the gauge pressure within a fluid?
fluid density, depth, free-fall acceleration
Energy applied to matter that changes the motion of the matter is called a __________.
force
Applying the brakes on a bicycle decelerates the bicycle (accelerates it in the negative direction) and causes a change in the bicycle's velocity because the bicycle slows down. Brakes therefore exert a
force.
Motion that is determined only by the action of gravity on an object is called
free fall
Acceleration due to gravity is also called
free-fall acceleration
Which of the following terms in the equation for fluid pressure as a function of depth would not be the same in zero gravity?
free-fall acceleration
For a system in simple harmonic motion, which of the following is the number of cycles or vibrations per unit of time?
frequency
What force primarily keeps our world somewhat stable, rather than in chaotic motion?
friction
What provides the centripetal force for a car driving on a circular track?
friction
Which of the following forces always works in a direction opposite to the direction of motion (when an object is moving)?
friction
How is energy transferred as heat always directed?
from an object at high temperature to an object at low temperature
When calculating the gravitational force between two extended bodies, you should measure the distance
from the center of each body.
A ____ is a fluid that has neither a definite volume nor a definite shape.
gas
In a pendulum, at its height, all mechanical energy is gravitational potential energy, and is equal to mgh . At the bottom of its swing, all energy is kinetic and is expressed at 0.5 mv^2 . If mechanical energy is conserved, which of the following equations applies?
gh = 0.5 v^2
If a scientist uses a triple beam balance to measure the mass of an object, and reports the mass as 18.3010 kg, what are the smallest markings on the balance?
grams
Which of the following is constant (never changes value)?
gravitational acceleration
What are the two forms of potential energy that can be included in the equation for mechanical energy? ...\∑PE...
gravitational and elastic
Which of the following forces is NOT used in the equation for the coefficient of friction?
gravitational force
The degree to which an object attracts other objects is measured by the object's
gravitational mass.
What form of energy is associated with the position of an object in Earth's gravitational field?
gravitational potential energy
What provides the centripetal force for the moon's orbit around Earth?
gravity
The centripetal force responsible for the circular motion of heavenly bodies, such as planets and comets, is
gravity.
As a basketball player starts to jump for a rebound, the player begins to move upward faster and faster until his shoes leave the floor. At the moment the player begins to jump, the force of the floor on the shoes is
greater than the player's weight.
The motion of a pendulum is
harmonic a small angles.
A person moving in a vibrationless airplane would see a falling crate differently from an observer on the ground. The observer in the airplane
has a frame of reference as valid as the one for the observer on the ground
Newton's First Law states that, unless an unbalanced external force is applied, an object will remain at rest or continue at constant velocity. The converse is also true, that a body at rest or at constant velocity
has a net external force of zero.
Two objects are traveling in opposite lines away from a set point. Both have the same steady speed of 66 km/hour. The objects
have the same speed, but their velocities have opposite signs
Which of the following is a fluid?
helium
To which of the following is high temperature related?
high particle kinetic energy
A projectile is dropped at the same time as one given a horizontal velocity over a level surface. Neglecting air resistance, they will
hit the ground at the same time
In simple harmonic motion, amplitude is a measure of
how far away the moving object gets from the equilibrium point.
A good example of a system that is working toward thermal equilibrium is
iced water.
In Newton's Second Law, F = ma, the element of time is in the acceleration variable. In the impulse-momentum theorem, the element of time is in the
impulse expression, Ft, and the velocity component of momentum.
The centripetal force on an object in circular motion is
in the same direction as the centripetal acceleration.
When two objects are in physical contact with each other, and they have the same temperature, they are
in thermal equilibrium.
A closely grouped set of data points that are not close to the expected values are
inaccurate, but precise
Some authors do not include screws in a list of simple machines because a screw is simply a(n) _________ that has been wound into a circular shape.
inclined plane
Increasing the net amount of energy transferred as heat from a high-temperature substance to the engine, or decreasing the net amount of energy transferred as heat from the engine to a low-temperature substance, or both of these conditions together will __________done by the engine.
increase the net amount of work
In most cases, air resistance _______ with increasing speed.
increases
Which of the following does NOT change momentum?
increasing the normal force acting on an object, as when a runner leaves the sand and runs on the sidewalk.
Two bean bags are thrown together. They smack into each other, but both drop apart. What type of collision is this?
inelastic
A ball is whirled on a string, then the string breaks. What causes the ball to move off in a straight line?
inertia
A tether ball is tied to a string and whirled in a horizontal circular path at a constant speed. What causes the ball and string to move away from the post?
inertia
When a car makes a sharp left turn, what causes the passengers to move toward the right side of the car?
inertia
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
instantaneous velocity
When two waves occupy the same place at the same time, they
interfere.
Which of the following characteristics of light pertains to its wave nature and not to its ray nature?
interference
In an isovolumetric process for an ideal gas, the system's change in the energy as heat is equivalent to a change in which of the following?
internal energy
What are the energies associated with atomic motion called?
internal energy
According to the first law of thermodynamics, the difference between energy transferred to or from a system as heat and energy transferred to or from a system by work is equivalent to which of the following?
internal energy change
When a pendulum, roller coaster, or any other body that goes up and down, ascends to its maximum height, then begins to descend, its energy _________________.
is being converted mainly from potential to kinetic energy
Under normal conditions, water flows smoothly, has little internal friction, and does not form eddies. In such conditions, water
is close to an ideal fluid.
When an object is moving with uniform circular motion, the object's tangential speed
is constant.
When an object is moving with uniform circular motion, the centripetal acceleration of the object
is directed toward the center of motion.
Which thermodynamic process takes place at a constant temperature so that the internal energy of a system remains unchanged?
isothermal
The SI base unit used to measure mass is the
kilogram
Which of the following energy forms is associated with an object in motion?
kinetic energy
At the melting point of ice, energy applied to the ice does not change its temperature. That is because the heat becomes the
latent heat of the change from solid to liquid.
To analyze the flight of a basketball through the air in a gymnasium, which facts are most relevant?
launch point, angle, and force; mass, volume, and shape of the basketball; force of gravity; air resistance
The first law of thermodynamics is based upon
law of conservation of energy
What two dimensions, in addition to mass, are commonly used by physicists to derive additional measurements?
length and time
What occurs when a system's disorder is increased?
less energy is available to do work
One implication of the second law of thermodynamics is that all machines have efficiencies
less than 1 and greater than or equal to 0.
An electrical power plant manages to transfer 88 percent of the heat produced in the burning of fossil fuel to convert water to steam. Of the heat carried by the steam, 40 percent is converted to the mechanical energy of the spinning turbine. Which best describes the overall efficiency of the heat-to-work conversion in the plant?
less than 40 percent
A ______has a definite volume, but a gas does not.
liquid
What is the abbreviation of the SI unit of velocity?
m/s
The rules of science shorthand are usually the same as algebra. Using your knowledge of algebra, answer the following question: The notation m/s^2 is the same as __________________.
m/s/s
Which of the following is the same unit as m/s/s?
m/s^2
A vector quantity is a quantity that has
magnitude and direction
The length of a force vector represents the
magnitude of the force
What three properties of a substance affect the amount of energy transferred as heat to or from the substance?
mass, temperature change, specific heat capacity
A measure of the quantity of matter is
mass.
If a cat moves from a negative position to a positive position, is the cat's displacement negative or positive?
positive
The solution that Archimedes found to test whether the king's crown was pure gold involved
measuring the density and comparing it to that of pure gold.
Electromagnetic waves can move through empty space, but mechanical waves require a ____________________ through which to travel.
medium
The most appropriate SI unit for measuring the length of an automobile is the
meter
Which of the following prefixes indicates one-millionth (10 -6 )?
micro-
The impulse experienced by a body is equivalent to the body's change in
momentum.
A k value of 110 for a spring indicates that the spring would require _____force to stretch than for a spring with a k value of 66.
more
Which of the following do NOT produce lift in an airplane?
more rapid air flow above the wing than below
On a wheel and axle, for a given force applied to the wheel, a larger wheel will provide _____ a smaller wheel.
more torque than
A passenger on a bus moving east sees a man standing on a curb. From the passenger's perspective, the man appears to
move west at a speed that is equal to the bus's speed.
Two substances of similar particle mass have two different temperatures. The particles of the hotter one are
moving faster.
Which of the following best describes the momentum of two bodies after a two-body collision if the kinetic energy of the system is conserved?
must also be conserved
If a pendulum is adjusted so that its frequency changes from 10 Hz to 20 Hz, its period will change from n seconds to
n/2 seconds.
If an object is decelerating (slowing down), the slope of the tangent line on the velocity-time graph at that instant will be
negative
Name the two SI units for work.
newton-meters and joules
A crate is released on a frictionless plank inclined at angle q with respect to the horizontal. Which of the following relationships is true? (Assume that the x-axis is parallel to the surface of the incline.)
none of the above
Two dogs are tugging on a toy. One dog pulls with a horizontal force of 14 N due north. The other is pulling due east with a horizontal force of 14 N. What is the direction of the net external horizontal force on the toy?
northeast
The same phenomenon, viewed from different frames of reference, will
often appear quite different
The Newton is defined as the force that can accelerate
one kilogram one meter/second/second.
Which of the following describes the direction of the static friction force?
opposite the net external force that would move an object in the absence of static friction
Friction always acts in a direction
opposite to the motion of an object.
Suppose longitudinal waves are generated in a long spring. The particles within the spring will vibrate _______the direction of wave motion about an equilibrium position.
parallel to
Two objects stick together and move with a common velocity after colliding. Identify the type of collision.
perfectly inelastic
Two objects stick together and move with the same velocity after colliding. Identify the type of collision.
perfectly inelastic
For a system in simple harmonic motion, which of the following is the time required to complete a cycle of motion?
period
The restoring force in a pendulum swing is the component of gravity that is ________ to the force of the string.
perpendicular
To use the Pythagorean theorem to add two vectors that are not perpendicular, resolve each vector into perpendicular components and add the components that lie along the same axis. The resultant vectors can be added by using the Pythagorean theorem because they are
perpendicular
In a a rope through which a transverse wave is passing, the particles vibrate back and forth in a direction ________the direction of wave motion.
perpendicular to
Heat energy can be transferred by conduction, convection, and
radiation.
Power is the_____. In other words, power is the energy transferred in a given time interval
rate at which energy is transferred.
Which of the following parameters does not depend on how resistant a spring is to being compressed or stretched?
relaxed length
An air hockey table provides a frictionless surface for studying motion. A resting puck on an air hockey table will
remain at rest until an unbalanced force is applied.
An astronaut in free-fall orbit around the Earth is weightless, but her mass
remains the same.
Air resistance is a form of friction because it is a _______. It acts in the direction opposite an object's motion.
retarding force
Placing water in a microwave oven gives the water ______________, which is converted to all three types by contact with other molecules.
rotational energy
In graphing, x and y values are standardized. Consequently , x and y values are treated as
scalars
In the following sentence, is the everyday meaning or the scientific meaning of work intended? A coach does work on the bleachers by moving them into place before the basketball game.
scientific meaning
The requirement that a heat engine must give up some energy at a lower temperature in order to do work corresponds to which law of thermodynamics?
second
Which of the following is not an example of laminar flow?
smoke twisting as it moves upward from a fire
Which of the following is absolutely necessary before measurements can be communicated to other researchers?
standardization of measurements
Which is NOT a step in the scientific method?
stating opinions and projections
A piece of chalk is dropped by a teacher walking at a speed of 1.5 m/s. From the teacher's perspective, the chalk appears to fall
straight down.
Energy transferred as heat occurs between two bodies in thermal contact when they differ in which of the following properties?
temperature
Which of the following is proportional to the kinetic energy of atoms and molecules?
temperature
The statement, Δ t = 20 s, means that
the change in time was 20 seconds
To find the x component of a vector, it is necessary to multiply the total vector magnitude by
the cosine of the angle
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
the direction of the car's final velocity, the magnitude of the car's final velocity, and the displacement of the car
If the sign of work is negative,
the displacement is in the direction opposite the force
A person carrying a suitcase is not doing work on it because
the force applied to the suitcase is upward, and has no component in the forward direction.
If you lift an apple from the ground to some point above the ground, the gravitational potential energy in the system increases. This potential energy is stored in
the gravitational field between Earth and the apple.
Which of the following is an example of a fluid?
the hot magma of lava
Which of the following most directly affects the period of a pendulum's swings on Earth's surface? (Recall that the equation for period length, T, has only one independent variable that changes on Earth's surface.)
the length of the string or connecting rod between the pivot and the mass
Two objects with different masses collide and bounce back after an elastic collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite in direction. After the collision,
the less massive object had gained momentum.
In an inelastic collision between two objects with unequal masses,
the momentum of one object will increase by the amount that the momentum of the other object decreases.
Which of the following most affects the wavelength of a mechanical wave moving through a medium? Assume that the frequency of the wave remains constant.
the nature of the medium
When an astronaut in orbit experiences apparent weightlessness,
the net gravitational force on the astronaut is not balanced by a normal force.
A vase is sitting upon an upright table. Which is the opposing force to gravity, which keeps the vase from moving downward?
the normal force
Which of the following would be an example of a cyclic process?
the operation of an internal combustion engine
What does the difference between gauge pressure and absolute pressure equal?
the pressure at the surface of the fluid
A more powerful motor can do
the same work in a shorter time interval
Satellites in geosynchronous orbits (orbiting at the same speed as Earth's rotation) are a good example of different frames of reference. To put a satellite into orbit requires a lot of energy and force, but to an observer on the ground looking up at a satellite in geosynchronous orbit,
the satellite does not move
In physics, a system includes
the things that interact to produce a physical result
Which of the following is NOT involved in figuring the total momentum of a system?
the total kinetic energy of the system
The law of conservation of momentum states that
the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.
Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other without spinning,
their momenta are equal but opposite.
Two swimmers relax close together on air mattresses in a pool. One swimmer's mass is 48 kg, and the other's mass is 55 kg. If the swimmers push away from each other,
their momenta are equal but opposite.
Two stationary skaters, who push each other apart, do not change
their total momentum.
In order for temperature to be accurate, the thermometer must come into ____ with the object, and thus the temperature value indicated by the thermometer is the temperature of both the thermometer and the object. By making the thermometer small with respect to the object, the object's temperature will change very little when in contact with the thermometer.
thermal equilibrium
As the temperature of a substance increases, its volume tends to increase due to
thermal expansion.
A baker makes a loaf of bread. Identify the area of physics that this involves.
thermodynamics
Which branch of physics studies the relationships of heat and energy?
thermodynamics
Which branches of physics are most involved with why and how a person might dive into a swimming pool to cool off on a hot day?
thermodynamics and mechanics
The statement by Newton that for every action there is an equal but opposite reaction is which of his laws of motion?
third
If a spring is stretched from a displacement of 10 cm to a displacement of 30 cm, the force exerted by the spring increases by a factor of ____________________.
three
The difference between work and energy, on one hand, and power on the other is
time.
Why do physicists often use models?
to explain the most basic features of phenomena
A lab technician runs a test with a sample whose test values are already known. What is the best reason for doing so?
to make sure that the test reagents and procedure are good
What is the natural tendency of an object that is in motion?
to remain in motion
If in simple harmonic motion, the moving object is on the right of the resting point, the force will be
to the left.
Which of the following quantities measures the ability of a force to rotate or accelerate an object around an axis?
torque
When heat is transferred by thermal conduction, the particles of the hotter substance collide with the particles of the cooler substance and
transfer their momentum and kinetic energy.
What three forms of kinetic energy can a polyatomic molecule have?
translational, rotational, vibrational
A wave travels through a medium. As the wave passes, the particles of the medium vibrate in a direction perpendicular to the direction of the wave's motion. The wave is
transverse.
Outside the U.S., where the Celsius scale is used, you should set thermostats at about _____ for comfortable rooms.
twenty degrees
A wrench with a lever arm of 0.50 meters will provide ______ torque as a wrench with a lever arm that is 0.25 meters long.
twice as much
The vertical distance from the crest to the trough of a transverse wave is
twice the amplitude.
Newton's third law of motion involves the interactions of
two objects and two forces.
Suppose a doorknob is placed at the center of a door. Compared with a door whose knob is located at the edge, what amount of force must be applied to this door to produce the torque exerted on the other door?
two times as much
Vectors can be added by placing them head to tail, or can be calculated ___________________.
using trigonometry (the Law of Cosines)
A crew member is walking on a tugboat that is pulling a barge. The tugboat is moving at a constant speed upstream in a river that has a constant downstream current. The velocity of the crew member with respect to the tugboat is v(1). What is the velocity of the crew member with respect to the barge?
v(1)
A jet airplane is traveling at 320 km/hr at an angle of 30.0 degrees to the ground. Find the horizontal component and the vertical component of the jet's velocity.
v(x) = 280 km/hr; v(y) = 160 km/hr
Which of the following is a physical quantity that has both magnitude and direction?
vector
Multiplying or dividing vectors by scalars results in
vectors
Which of the following is an example of a vector quantity?
velocity
The relationship between angular speed (w) and tangential speed, v t , is given by the formula,
w = v t / r.
A person sitting in a chair with wheels stands up, causing the chair to roll backward across the floor. The momentum of the chair
was zero while stationary and increased when the person stood.
The only significant exception to the rule that all substances expand when they are heated is that
water contracts as it melts (from 0 to 4 degrees C).
Two longitudinal waves of different frequencies pass through the same medium. Must the two waves have different velocities, wavelengths, or amplitudes?
wavelengths
The magnitude of the gravitational force acting on an object is
weight.
Friction was defined as a force to explain
why things stopped.
Which of the following relationships is indicated by a linear graph?
y = kx
Terminal velocity for a skydiver is when the force of air resistance matches the gravitational pull, so that the skydiver falls at a constant rate. For many skydivers, terminal velocity is about 100 m/s. If a skydiver fell for 11 seconds, would she be falling at terminal velocity? (Would her v f exceed 100 m/s?)
yes
Consider two identical wave pulses on a rope having a fixed end. Suppose the first pulse reaches the end of the rope, is reflected back, and then meets the second pulse. When the two pulses overlap exactly, what will be the amplitude of the resultant pulse?
zero
Two snowballs are traveling straight toward each other. One snowball has twice the mass of the other, but is moving at half the speed. The snowballs meet head-on in a perfectly inelastic collision. What is the total momentum of the system containing the two snowballs before the collision?
zero