Fall Final Exam AP Physics 1
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
A person is attracted toward the center of Earth by a 500-N gravitational force. The Earth is attracted toward the person with a force of
500 N
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
A change in the gravitational force acting on an object will affect the object's
weight
Recoil is noticeable if we throw a heavy ball while standing on roller skates. If instead we go through the motions of throwing the ball but hold onto it, our net recoil will be
zero
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 circular racetrack has a circumference of 6.3km. What angular speed, in revolutions per minute, does a racecar have if it has a linear speed of 199km/hr?
0.526 rpm
Two children are on a merry-go-round. Billy is a distance r from the center and Willy is a distance 3r from the center. What is the ratio of Willy's linear speed to Billy's linear speed?
3
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
How much work is done by the force described in the graph below?
5750 J
At what rate is a 60.0-kg boy using energy when he runs up a flight of stairs 10.0-m high, in 8.00 s?
735 W
A stone is thrown horizontally from the top of a cliff. One second after it has left your hand, its vertical distance below the top of the cliff is
5 m
According to the graph above, during which interval is the cat at rest?
5.0-10.0 s
The figure above shows the path of a ball tossed from a building. Air resistance is ignored. In the figure above, at which point is the ball's speed about equal to the speed at which it was tossed?
C
The graph above describes the motion of a ball. At what point does the ball have an instantaneous velocity of zero?
C
The figure above shows the path of a ball tossed from a building. Air resistance is ignored. In the figure above, the magnitude of the ball's velocity is greatest at location
D
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
Which of the following is an accurate statement?
If an object is acted on by a non-zero net external force, its momentum will not remain constant
When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed?
It is less than its initial speed
A space probe is directly between two moons of a planet. If it is twice as far from moon A as it is from moon B, but the net force on the probe is zero, what can be said about the relative masses of the moons?
Moon A is four times as massive as moon B
What are the units for a spring constant?
N/m
A container of water is lifted vertically 3.0 m then returned to its original position. If the total weight is 30 N, how much work was done?
No work was done
Can work be done on a system if there is no motion?
No, because of the way work is defined
What prevents satellites such as the space shuttle from falling?
Nothing; they are continually falling as they orbit the Earth.
The figure above shows the path of a ball tossed from a building. Air resistance is ignored. In the figure above, the magnitude of the ball's velocity is least at location
B
What is the path of a projectile (in the absence of friction)?
a parabola
The amount of gravitational force that acts on the space shuttle while in orbit is
almost as much as the shuttle's weight on the Earth's surface.
The diagram below shows the trajectories of two balls. The magnitude of the initial velocity is vi, the launch angle is q, and the horizontal and vertical components of the initial velocity are vxi and vyi. Compare the values of vyi. The value for ball A
is greater than the value for ball B
When is kinetic energy conserved?
in elastic collisions
Two objects move toward each other because of gravity. As the objects get closer and closer, the force between them
increases
A ball is whirled on a string, then the string breaks. What causes the ball to move off in a straight line?
inertia
If one object has twice as much mass as another object, it also has twice as much
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
The graph above describes the motion of a cyclist. The graph illustrates that the acceleration of the cyclist
is constant
Two objects collide and bounce off each other. Linear momentum
is definitely conserved
Two objects collide and stick together. Kinetic energy
is definitely not conserved
When an object is moving with uniform circular motion, the centripetal acceleration of the object
is directed toward the center of motion
When riding in an elevator on a bathroom scale, the scale will give a value equal to your true weight when the elevator (choose all that apply)
moves at constant speed, is at rest
Horses that move with the fastest linear speed on a merry-go-round are located
near the outside
When a rocket ship accelerating in outer space runs out of fuel, it
no longer accelerates
The graph above describes the motion of a ball. At what point is the velocity of the ball equal to its velocity at B?
none of the above
A large heavy truck and a small baby carriage roll down a hill. Neglecting friction, at the bottom of the hill, the baby carriage will have a greater
none of these
The formulas for rotational kinematics have a similar format to those for linear kinemtics. Which rotational quantity below is the analog for the linear quantity called velocity?
omega
A car goes around a curve of radius r at a constant speed v. Then it goes around the same curve at half of the original speed. What is the centripetal force on the car as it goes around the curve for the second time, compared to the first time?
one-fourth as big
Which of the following equations can be used to directly calculate an object's momentum, p?
p = mv
A sailboat of mass m is moving with a momentum p. How would you represent its kinetic energy in terms of these two quantities?
p2/(2m)
Which of the following energy forms is associated with an object due to its position?
potential energy
Which of the following is the rate at which energy is transferred?
power
Which of the following is the motion of objects moving in two dimensions under the influence of gravity?
projectile motion
The period of a satellite, the time it takes for a complete revolution, depends on the satellite's
radial distance
Angular velocity is expressed in units of
radians per second
Angular acceleration is expressed in units of
radians per second squared.
A soldier throws a grenade horizontally from the top of a cliff. Which of the following curves best describes the path taken by the grenade?
Parabola
A rubber ball and a lump of putty have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The putty sticks to the wall. Which objects experiences the greater momentum change?
the ball
Consider force 1 in the diagram below: Identify the 3rd Law Reaction Force for this force
the box pulling on the Earth
Consider force 2 in the diagram below: Identify the 3rd Law Reaction Force for this force.
the box pushing on the ramp
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
Planets would crash into the sun if it weren't for
their tangential velocities.
Consider the box shown in the diagram above. The forces act in the direction shown in the diagram. If the magnitudes of the forces are A=90N, B=110N, and C=200N, what is the direction of the acceleration of the box?
there is no acceleration
The formulas for rotational kinematics have a similar format to those for linear kinemtics. Which rotational quantity below is the analog for the linear quantity called displacement?
theta
The statement by Newton that for every action there is an equal but opposite reaction is which of his laws of motion?
third
To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the
time of impact is increased
A car goes around a curve of radius r at a constant speed v. What is the direction of the net force on the car?
toward the curve's center
The path of a projectile through space is called its
trajectory
A car goes around a curve of radius r at a constant speed v. Then it goes around a curve of radius 2r at speed 2v. What is the centripetal force on the car as it goes around the second curve, compared to the first?
twice as big
Newton's third law of motion involves the interactions of
two objects and two forces
The momentum of a 2000 kilogram car traveling at 20 meters per second is
40,000 kg·m/sec
Moustapha Jones reaches the bottom of a hill on his bike moving at a speed of 8.6 m/s when his chain breaks. He coasts up the hill until he comes to a stop after 3.5 s. Find his acceleration while on the hill, and the distance he travelled up the hill.
-2.46m/s2, 15.1m
A driver, traveling at 22 m/s, slows down her 2000 kg car to stop for a red light. What work is done by the friction force against the wheels?
-4.84x10^5 J
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
Two billiard balls having the same mass and speed roll toward each other. What is their combined momentum after they meet?
0
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).
A 50-N object was lifted 2.0 m vertically and is being held there. How much work is being done in holding the box in this position?
0 J
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
Two children are on a merry-go-round. Billy is a distance r from the center and Willy is a distance 3r from the center. What is the ratio of Willy's period of revolution to Billy's period of revolution?
1
If you pitch a baseball with twice the kinetic energy you gave it in the previous pitch, the magnitude of its momentum is
1.41 times as much
An object hits a wall and bounces back with half of its original speed. What is the ratio of the final kinetic energy to the initial kinetic energy?
1/4
The free-body diagram shown above represents a car being pulled by a towing cable. In the diagram, which of the following is the gravitational force acting on the car?
14 700 N
Suppose the circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second when you are riding the bicycle, then your speed will be
2 m/s
Car J moves twice as fast as car K, and car J has half the mass of car K. The kinetic energy of car J, compared to car K is
2 to 1
A 0.200-kg mass attached to the end of a spring causes it to stretch 5.0 cm. If another 0.200-kg mass is added to the spring, the potential energy of the spring will be
4 times as much.
What braking force is needed to stop a 1300-kilogram car moving at 10 m/sec in a time of 3 seconds?
4333 newtons
At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range?
45°
A 63kg man rides in an elevator while standing on a bathroom scale calibrated to read force in Newtons. As the elevator moves upwards it slows with an acceleration of magnitude 1.9 m/s2. The scale displays:
497.7 N
A disk spins at a rate of 55.78 revolutions per minute. Calculate the angular speed in radians per second.
5.841 radians/second
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
6 N
A 67kg man rides in an elevator while standing on a bathroom scale calibrated to read force in Newtons. As the elevator moves downwards at a constant speed the scale displays:
656.6 N
A 67kg man rides in an elevator while standing on a bathroom scale calibrated to read force in Newtons. As the elevator starts to move upwards it speeds up with an acceleration of magnitude 1.9 m/s2. The scale displays:
783.9 N
A ball is thrown at an original speed of 8.0 m/s at an angle of 35° above the horizontal. What is the speed of the ball when it returns to the same horizontal level?
8.0 m/s
Moustapha Jones drives east at 100km/hr for 3 hours then back west at 80km/hr for 1.5 hours. Which pair of answers gives his average speed and average velocity?
93.3km/hr, 40km/hr east
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
The diagrams below represent the free-body diagrams of a parachutist at her various stages of descent after a jump from an airplane. Which diagram shows the parachutist at the moment of her jump?
Arrow pointing down
A soccer ball is kicked into the air with an initial vertical velocity of +49 meters per second and a horizontal velocity of +19.6 meters per second. The diagram representing the vertical and horizontal velocity of the ball after 2 seconds of flight is:
B
A man starts his car from rest and accelerates at 1 m/s2 for 4 seconds. He then continues at a constant velocity for 10 seconds until he sees a tree blocking the road and applies brakes. The car, decelerating at 1 m/s2, finally comes to rest. Which of the following graphs represents the motion correctly?
Big Trapezoid
A man starts his car from rest and accelerates at 1 m/s2 for 4 seconds. He then continues at a constant velocity for 10 seconds until he sees a tree blocking the road and applies brakes. The car, decelerating at 1 m/s2, finally comes to rest. Which of the following graphs represents the motion correctly?
Big trapezoid
A small object collides with a large object and sticks. Which object experiences the larger magnitude of momentum change?
Both objects experience the same magnitude of momentum change.
Which of the following equations can be used to directly calculate the change in an object's momentum?
Change in p = F change in t
Which graph best describes the movement of an object on which no net force is exerted?
Distance x time that is positive and linear
An object is placed exactly halfway between the Earth and moon. The object will fall toward the
Earth.
Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the coefficient of static friction between the boxes?
F/(4mg)
Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?
F/4
Which of the following statements does not describe force?
Force causes objects at rest to remain stationary
In this text, which of the following symbols represents the constant of universal gravitation?
G
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
Is it possible for an object moving with a constant speed to accelerate? Explain.
Yes, although the speed is constant, the direction of the velocity can be changing.
When a car's velocity is positive and its acceleration is negative, what is happening to the car's motion?
The car slows down
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
The car speeds up
Two children of equal mass are on a merry-go-round. Which child experiences the greater centripetal force?
The child near the edge
Two children are on a merry-go-round. Which child has the faster linear speed?
The child near the edge.
What are the units of the coefficient of friction?
The coefficient of friction has no units
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
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
A large mass M and a small mass m, (identical in all aspects except for the masses) are dropped from a great height. Which statement about their terminal velocities is correct?
The larger mass will have the larger terminal velocity since a larger air resistance and thus a larger speed is required to balance its larger weight
A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?
The total momentum both before and after the collision is zero
A truck weighs twice as much as a car, and is moving at twice the speed of the car. Which statement is true about the truck's kinetic energy compared to that of the car?
The truck has 8 times the kinetic energy of the car.
Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street?
They are traveling at the same speed
What is the common formula for work? Assume that W is the work, F is a constant force, mc004-1.jpgv is the change in velocity, and d is the displacement.
W = Fd
You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.
Work is - on the way up and + on the way down
A feather will fall through the air more slowly than a brick because of ____.
air resistance
Describe the energy of a car driving up a hill.
both kinetic and potential
If the sun were twice as massive
both of these
What type of acceleration does an object moving with constant speed in a circular path experience?
centripetal acceleration
Suppose a ball is thrown straight up. What is its acceleration just before it reaches its highest point?
exactly g
What causes a moving object to change direction?
force
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the
force the glove exerts on the ball
A free-body diagram represents all of the following except
forces exerted by the object
A force does work on an object if a component of the force
is parallel to the displacement of the object.
A feather is in free fall when the force of gravity
is the only force acting on it
What are the SI units for momentum?
kg m/s
What is the SI unit of acceleration?
m/s^2
A force is a vector quantity because it has both
magnitude and direction
The length of a force vector represents the
magnitude of the force
A kilogram is a measure of an object's
mass
A golf ball traveling 3.0 m/s to the right collides in a head-on collision with a stationary bowling ball in a friction-free environment. If the collision is almost perfectly elastic, the speed of the golf ball immediately after the collision is
slightly less than 3.0 m/s
Of the following, which is not a unit of power?
watt/second
A car goes forward along a level road at constant velocity. The additional force needed to bring the car into equilibrium is
zero
A ball is thrown up from street level and returns to its original height as shown in the graph below. What is the acceleration of the ball at 3s?.
-9.8 m/s^2
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
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
0 N
A ball is thrown up from street level and returns to its original height as shown in the graph below. How fast is the ball moving after 3s?
0 m/s
According to the graph above, during which interval does the cat have the greatest positive velocity?
0.0-5.0 s
A circular racetrack has a circumference of 6.5km. What angular speed, in radians per second, does a racecar have if it has a linear speed of 243km/hr?
0.065 rad/sec
A machine part is measured to have an angular speed of 67rad/sec. What is the time period for one revolution?
0.094 s
A bullet fired horizontally over level ground hits the ground in 0.5 second. If it had been fired with twice the speed in the same direction, it would have hit the ground in
0.5 s
An object is dropped and freely falls to the ground with an acceleration of 1 g. If it is thrown upward at an angle instead, its acceleration will be
1 g downward
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is
10 N
According to the graph above, the cat has the fastest speed during which interval?
10.0-15.0 s
A weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above the Earth's surface. How much would she weigh there?
100 N
A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground?
100 m
A baseball player bats a ball with a force of 1000 N. The reaction force that the ball exerts against the bat is
1000 N
A cart of mass 5.3 kg initially moving at 5 m/s is subject to an impulse which can be found from the graph. What is the final speed of the car if the force acts in the direction of the intial velocity.
11.0 m/s
Consider the box shown in the diagram above. If the box is in quilibrium and force A has magnitude 65N and force B has magnitude 45N, what is the magnitude of force C?
110N to the left
A roller coaster starts from rest at a point 45 m above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?
17 m/s
A roller coaster starts at a point 30 m above the bottom of a dip with a speed of 25 m/s (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 45 m above the bottom of the dip?
18 m/s
A roller coaster starts with a speed of 5.0 m/s at a point 45 m above the bottom of a dip (See Fig. 6-2). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?
18 m/s
The diagram below represents a box sliding down an incline: The force of friction acting on the box is directed toward:
2
A 2-kilogram piece of clay moving at 4 m/sec strikes and sticks to a second 4-kilogram piece of clay moving at 1 m/sec in the opposite direction. Calculate the speed of the combined piece of clay.
2/3 m/sec
A 0.2 kg baseball is pitched with a velocity of 46 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?
21 kg m/s
A force is applied as shown in the graph. What impulse is given by this force?
25 N s
A brick is moving at a speed of 3 m/s and a pebble is moving at a speed of 5 m/s. If both objects have the same kinetic energy, what is the ratio of the brick's mass to the rock's mass?
25 to 9
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 approximate angular speed of the earth as it orbits the sun in radians per second?
2´10^-7 radians/second
Two children are on a merry-go-round. Billy is a distance r from the center and Willy is a distance 3r from the center. What is the ratio of Willy's centripetal acceleration to Billy's centripetal acceleration?
3
A 4 kg ball has a momentum of 12 kg m/s. What is the ball's speed?
3 m/s
Two projectiles are fired from ground level at equal speeds but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. The projectile to hit the ground first will be the one fired at (neglect air resistance)
30 degrees
A ball is thrown up from street level and returns to its original height as shown in the graph below. Use the graph to find the initial velocity of the ball.
30 m/s
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is
3000 N
A disk spins at a rate of 49.09 revolutions per second. Calculate the angular speed in radians per second.
308.4 radians/second
An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance away?
30° and 60°
A disk spins and makes 52.09 revolutions. Through how many radians did the disk spin?
327.3 radians
A 6.3-kg wooden block is pulled across a carpet with a force of F = 36 N. The block begins at rest and accelerates to a velocity of 0.25 m/s in 0.50 s. What is the force of friction acting on the block?
33 N
A disk with a diameter of 20cm spins at a rate of 32.44 revolutions per minute. Calculate the linear speed of the edge of the disk in cm/s..
34 cm/s
The kinetic friction force between a 60.0-kg object and a horizontal surface is 50.0 N. If the initial speed of the object is 25.0 m/s, what distance will it slide before coming to a stop?
375 m
An asteroid exerts a 360-N gravitational force on a nearby spacecraft. If the spacecraft moves to a position three times as far from the center of the asteroid, the force will be
40 N
A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is
400 N
Which of the following system of forces provides the block the highest net force?
41 N to the right and 54 N to the left
A ball is thrown vertically upward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the second ball to that of the first ball? (How many times higher does the second ball go than the first ball?)
4:1
A 10-N force is needed to move an object with a constant velocity of 5.0 m/s. What power must be delivered to the object by the force?
50 W
What is the force of gravity on a 500-newton woman standing on the Earth's surface?
500 N
When a woman stands at rest with both feet on a scale, it reads 500 N. When she gently lifts one foot, the scale reads
500 N
An object is released from rest on a planet that has no atmosphere. The object falls freely for 3.0 meters in the first second. What is the magnitude of the acceleration due to gravity on the planet?
6.0 m/s^2
The driver of a car traveling at 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s.
6.79 m/s^2
If a 40,000 kilogram rocket were traveling from its launch pad at a speed of 150 meters per second, 800 kilograms of gases would be expelled from the rocket at a speed of about:
7,500 m/sec
The driver of a car traveling at 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s. If the car skids in a straight line for the entire length of the stopping distance, how long are its skid marks?
7.0 x 10^1 m
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
Consider the box shown in the diagram above. If the box is in quilibrium and force A has magnitude 55N and force C has magnitude 125N, what is the magnitude of force B?
70N to the right
A man rides in an elevator while standing on a bathroom scale calibrated to read force in Newtons. As the elevator starts to move upwards it speeds up with an acceleration of magnitude 2.1 m/s2. The scale displays a force of 844.9. What is the man's mass?
71 kg
Pulling on a rope with a force of 100 newtons at an angle mc010-1.jpg of 30 degrees, Cheung pulls a box across a surface at a constant speed: The magnitude of the frictional force resisting the motion is ____ newtons.
87
How many joules of energy are used by a 1.0 hp motor that runs for 1.0 hr? (1 hp = 746 W)
: 2.7 x10^6 J
What is the correct unit of work expressed in SI units?
: kg m^2/s^2
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
The figure above shows the path of a ball tossed from a building. Air resistance is ignored. At what point of the ball's path shown in the figure above is the vertical component of the ball's velocity zero?
B
A boy and a girl are riding a merry-go-round which is turning at a constant rate. The boy is near the outer edge, while the girl is closer to the center. Who has the greater tangential acceleration?
Both have zero tangential acceleration
A ball is thrown straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming down.
Both its velocity and its acceleration point downward
A 4.0-kg mass is moving with speed 2.0 m/s. A 1.0-kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant braking force, and are brought to rest. Which object travels the greater distance before stopping?
Both travel the same distance.
Which of the following represents the freebody diagram for a box being pulled at constant speed up a rough ramp?
Box with 4 arrows
Which of the following represents the freebody diagram for a box at rest on a rough ramp?
Box with three arrows: one pointing up (Fn), one pointing the the left side (friction) and one pointing down (mg)
Which of the following represents the freebody diagram for a box at sliding at constant speed down a smooth (frictionless) ramp?
Box with three arrows: one pointing up (Fn), one pointing the the left side (friction) and one pointing down (mg)
Which of the following represents the freebody diagram for a box being pulled at constant speed up a smooth (frictionless) ramp?
Box with three arrows: one pointing up (Fn), one pointing the the left side (friction) and one pointing down (mg)
Which of the following represents the freebody diagram for a box held at rest on a smooth (frictionless) ramp.
Box with three arrows: one pointing up (Fn), one pointing the the left side (friction) and one pointing down (mg)
At time t = 0, Car X traveling with speed v0 passes Car Y. which is just starting to move. Both cars then travel on two parallel lanes of the same straight road. The graphs of speed v versus time t for both cars are shown above. Which of the following is true at time t = 20 seconds?
Car Y is behind car X
At time t = 0, Car X traveling with speed v0 passes Car Y. which is just starting to move. Both cars then travel on two parallel lanes of the same straight road. The graphs of speed v versus time t for both cars are shown above. From time t = 0 to time t = 40 seconds, the areas under both curves are equal. Therefore, which of the following is true at time t = 40 seconds?
Car Y is passing car X
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger centripetal acceleration?
Child A
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger linear displacement?
Child A
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger tangential acceleration?
Child A
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger tangential speed?
Child A
The diagrams below represent the free-body diagrams of a parachutist at her various stages of descent after a jump from an airplane. Which diagram shows the parachutist at terminal velocity?
Circle with even arrows pointing up and down
The diagrams below represent the free-body diagrams of a parachutist at her various stages of descent after a jump from an airplane. Which diagram shows the parachutist at some time after the jump but before reaching terminal velocity?
Circle with the down arrow longer than the up arrow
The diagrams below represent the free-body diagrams of a parachutist at her various stages of descent after a jump from an airplane. Which diagram shows the parachutist just after opening her parachute?
Circle with the up arrow longer than the down arrow
The graph above describes the motion of a ball. At what point is the speed of the ball equal to its speed at B?
D
Which of the following equations expresses Newton's law of universal gravitation?
Fg = (G(m1m2))/r^2
A horizontal force accelerates a box from rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?
It increases to more than double its original value
Consider a particle moving with constant speed such that its acceleration of constant magnitude is always perpendicular to its velocity.
It is moving in a circle
Two cars collide head-on on a level friction-free road. The collision was completely inelastic and both cars quickly came to rest during the collision. What is true about the velocity of this system's center of mass?
It was always zero
Suppose a ball is thrown downward in the absence of air resistance. Make a statement concerning its acceleration
Its acceleration is constant
When an object is released from rest and falls in the absence of friction, which of the following is true concerning its motion?
Its acceleration is constant
When an object is released from rest and falls in the absence of friction, which of the following is true concerning its motion?
Its acceleration is constant.
Suppose a ball is thrown straight up. Make a statement about the velocity and the acceleration when the ball reaches the highest point.
Its velocity is zero and its acceleration is not zero
Suppose a ball is thrown straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.
Its velocity points upward and its acceleration points downward
Which of the following are not units of power?
J
Two children ride on a merry-go-round, George is at a greater distance from the axis of rotation than Jacques. It is a true statement that
Jacques and George have the same angular velocity
Two children ride on a merry-go-round, George is at a greater distance from the axis of rotation than Jacques. It is a true statement that
Jacques has a smaller tangential speed than George
The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because
Jupiter's radius is 10 times the Earth's radius.
An acorn falls from a tree. Compare its kinetic energy K, to its potential energy U
K increases and U decreases
A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?
K is less than U
Which graph most accurately describes the relationship between the force of kinetic friction and the normal force?
Linear and positive graph
A ball is dropped from the top of a building. In the absence of air resistance which of the following could be a velocity time graph for the falling ball?
Linear negative graph
A ball is thrown up from street level and returns to its original height. Which of the following could be a velocity-time graph of the ball's trip?
Linear negative graph
A ball is tossed straight up and then falls to the same height from which it was released. Which graph below properly shows how the velocity of the ball changes with time from the moment of release to the moment before impact?
Linear negative graph
The driver of a car traveling at 110 km/h slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s. Which is the most accurate plot of velocity versus time for the braking car?
Linear negative graph
In which of the following sentences is work used in the scientific sense of the word?
Sam and Rachel pushed hard, but they could do no work on the car.
While standing on a stationary skateboard, Jolene tosses a heavy ball horizontally toward one end of her skateboard. The skateboard moves. Assuming there is no friction in the system when the ball is tossed, which statement about the momentum of the heavy ball is INCORRECT?
The directions of the ball's momentum and Jolene's momentum are the same
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
A brick is dropped from the top of a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.
The two bricks accelerate at the same rate
An object moves in a circular path at a constant speed. Compare the direction of the object's velocity and acceleration vectors.
The vectors are perpendicular.
Consider two masses m1 and m2 at the top of two frictionless inclined planes. Both masses start from rest at the same height. However, the plane on which m1 sits is at an angle of 30° with the horizontal, while the plane on which m2 sits is at 60°. If the masses are released, which is going faster at the bottom of its plane?
They both are going the same speed
Two children are on a merry-go-round. Which child has the faster angular speed?
They both have the same speed
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill. Which rises to a greater height?
They both slide to the same height
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger angular displacement?
They have the same non-zero angular displacement.
Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger angular speed?
They have the same non-zero angular speed.
A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same height. Ignore air resistance. Compare the times of fall of the two bullets.
They hit at the same time
Which of the following is a true statement about the conservation of energy?
Total energy is always conserved.
Is it possible for a system to have negative potential energy?
Yes, since the choice of the zero of potential energy is arbitrary
Which of the following does not exhibit parabolic motion?
a flat piece of paper released from a window
A packing crate slides down an inclined ramp at constant velocity. Thus we can deduce that
a frictional force is acting on it
Which of the following is not an example of projectile motion?
a hot-air balloon drifting toward Earth
Which of the following is an example of projectile motion?
a thrown baseball
Gravitational potential energy is always measured in relation to
a zero level
When riding in an elevator on a bathroom scale, the scale will give a value smaller than your true weight when the elevator
accelerates downwards
When riding in an elevator on a bathroom scale, the scale will give a value larger than your true weight when the elevator
accelerates upwards
The upward force on an object falling through the air is ____.
air resistance
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
all of the above
Which of the following can be a centripetal force?
all of the above
The circular path of a satellite orbiting the Earth is characterized by a constant
all of these
The formulas for rotational kinematics have a similar format to those for linear kinemtics. Which rotational quantity below is the analog for the linear quantity called acceleration?
alpha
Which has the greater mass?
an automobile battery
Two balls are thrown horizontally. Ball C is thrown with a force of 20 N, and ball D is thrown with a force of 40 N. Assuming all other factors are equal, ball D will fall toward the ground
at the same rate as ball C
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
A pilot drops a bomb from a plane flying horizontally at a constant speed. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will
be over the bomb
If a nonzero net force is acting on an object, then the object is definitely
being accelerated
A supplier wants to make a profit by buying metal by weight at one altitude and selling it at the same price per pound at another altitude. The supplier should
buy at a high altitude and sell at a low altitude.
What force is needed to make an object move in a circle?
centripetal force
What is the term for the net force directed toward the center of an object's circular path?
centripetal force
The force of friction between two surfaces can be reduced by all of the following EXCEPT:
changing rolling friction to sliding friction
The movement of an object or a point mass at a constant speed around a circle that has a fixed radius is called uniform:
circular motion
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its vertical component of velocity
decreases
If the net work done on an object is negative, then the object's kinetic energy
decreases
According to Newton, doubling the distance between two interacting objects
divides by 4 the gravitational force between them.
If a turntable's rotational speed is doubled, then the linear speed of a pet hamster sitting on the edge of the record will
double
Your pet hamster sits on a record player whose angular speed is constant. If he moves to a point twice as far from the center, then his linear speed
doubles.
The figure above shows the path of a ball tossed from a building. Air resistance is ignored. In the figure above, the horizontal component of the ball's velocity at A is
equal to the horizontal component of its initial velocity
An object is released from rest a height h above the ground. A second object with four times the mass of the first if released from the same height. The potential energy of the second object compared to the first is
four times as much
You are throwing a ball for the second time. If the ball leaves your hand with twice the velocity it had on your first throw, its horizontal range R (compared to your first serve) would be
four times as much
Acceleration due to gravity is also called
free-fall acceleration
The force that resists the motion of objects or surfaces in contact with one another is called ____ force.
frictional
When calculating the gravitational force between two extended bodies, you should measure the distance
from the center of each body.
In this text, which of the following symbols represents gravitational field strength?
g
According to Newton, the greater the masses of interacting objects, the
greater the gravitational force between them.
Which would hit the ground first if dropped from the same height in a vacuum-a feather or a metal bolt?
hey would hit the ground at the same time
Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. As time progresses, the distance between them
increases
If the net work done on an object is positive, then the object's kinetic energy
increases
Glaciers push rocks in front of them. Before a stationary rock starts moving as a result of the force Fglacier exerted on it, the static friction between the rock and the ground
increases until it is equal to the product of ms and the normal force on the rock
If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is
inertia
When a car makes a sharp left turn, what causes the passengers to move toward the right side of the car?
inertia
Which of the following is the tendency of an object to maintain its state of motion?
inertia
When an object is moving with uniform circular motion, the object's tangential speed
is constant.
When an object experiences uniform circular motion, the direction of the net force is
is directed toward the center of the circular path
When an object experiences uniform circular motion, the direction of the acceleration is
is directed toward the center of the circular path.
A falling object's terminal velocity is reached when the force of gravity
is equal to the force of air resistance
The diagram below shows the trajectories of two balls. The magnitude of the initial velocity is vi, the launch angle is q, and the horizontal and vertical components of the initial velocity are vxi and vyi. Compare the values of qi. The value for ball A
is equal to the value for ball B
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
The diagram below shows the trajectories of two balls. The magnitude of the initial velocity is vi, the launch angle is q, and the horizontal and vertical components of the initial velocity are vxi and vyi. Compare the values of vi. The value for ball A
is greater than the value for ball B
The diagram below shows the trajectories of two balls. The magnitude of the initial velocity is vi, the launch angle is q, and the horizontal and vertical components of the initial velocity are vxi and vyi. Compare the values of vxi. The value for ball A
is greater than the value for ball B
You are pushing a rock along level ground and making the rock speed up. How does the size of the force you exert on the rock compare with the size of the force the rock exerts on you? The force you exert
is the same size as the force the rock exerts on you
A newton is equivalent to which of the following quantities?
kg m/s^2
What is the correct unit of power expressed in SI units?
kg m^2/s^3
Which of the following energy forms is associated with an object in motion?
kinetic energy
The main difference between kinetic energy and potential energy is that
kinetic energy involves motion, and potential energy involves position
Consider the box shown in the diagram above. The forces act in the direction shown in the diagram. If the magnitudes of the forces are A=90N, B=110N, and C=210N, what is the direction of the acceleration of the box?
left
To overcome static friction to start an object sliding on a level surface, a 100-newton force is used. The magnitude of the force needed to keep the object the sliding is:
less than 100 newtons
A woman on the surface of the Earth has a mass of 50 kilograms and a weight of 490 newtons. If the woman were floating freely inside a space habitat far away from Earth, she would have
less weight and the same mass
A "weightless" astronaut in an orbiting shuttle is
like the shuttle, pulled by Earth's gravitation.
Which of the following units is the SI unit of velocity?
meter per second
It's more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, because
mk < ms
The impulse experienced by a body is equivalent to the body's change in
momentum
The reason the moon does not crash into the Earth is that the
moon has a sufficient tangential speed
A ball drops some distance and gains 30 J of kinetic energy. Do not ignore air resistance. How much gravitational potential energy did the ball lose?
more than 30 J
In the graph above, what is the correct description of any location to the left of the zero?
negative position
Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them is also doubled, then the force between them is
none of these
Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in their speeds
remains constant
Roll a bowling ball off the edge of a table. As it falls, its horizontal component of velocity
remains constant
If you push twice as hard against a stationary brick wall, the amount of work you do
remains constant at zero.
If the net work done on an object is zero, then the object's kinetic energy
remains the same
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its horizontal component of velocity
remains unchanged
A rifle recoils while firing a bullet. The speed of the rifle's recoil is small because the
rifle has much more mass than the bulle
Consider the box shown in the diagram above. The forces act in the direction shown in the diagram. If the magnitudes of the forces are A=80N, B=50N, and C=110N, what is the direction of the acceleration of the box?
right
If you drop a stone into a hole drilled all the way to the other side of the Earth (neglect the molten core), the stone will
speed up until it gets to the center of the Earth.
The graph above describes the motion of a cyclist. During the interval shown, the cyclist is
speeding up
When riding in an elevator on a bathroom scale, the scale will give a value smaller than your true weight when the elevator (choose all that apply)
starts its downwards journey, is stopping on the way up
When riding in an elevator on a bathroom scale, the scale will give a value larger than your true weight when the elevator (choose all that apply)
starts its upwards journey, is stopping on the way down
The force that keeps you from sliding on an icy sidewalk is
static friction
An object moves in a circle of radius R at constant speed with a period t. If you want to change only the period in order to cut the object's acceleration in half, the new period should be:
t squareroot 2
On a plot of Force versus position (F vs. x), what represents the work done by the force F?
the area under the curve
If the sign of work is negative,
the displacement is in the direction opposite the force.
Work is done when
the displacement is not zero
A hunter on level ground fires a bullet at an angle of 10 degrees above the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?
the dropped one
The quantity 1/2 kx^2 is
the elastic potential energy of the object
A hunter on level ground fires a bullet at an angle of 2 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?
the fired one
The free-body diagram shown above represents a car being pulled by a towing cable. In the diagram, the 5800 N force is
the force exerted by the towing cable on the car
Your weight is
the gravitational attraction force between you and the Earth
The quantity mgh is
the gravitational potential energy of the object.
The quantity 1/2 mv2 is
the kinetic energy of the object.
Strange as it may seem, it is just as hard to accelerate a car on a level surface on the moon as it is here on the Earth. This is because
the mass of the car is independent of gravity
The equation for the speed of an object in circular orbit is v1 = square root G (m/r). What does m represent in this equation?
the mass of the central object
The fastest moving planet in a solar system is
the planet nearest the sun
The quantity Fd/t is
the power supplied to the object by the force
Acceleration is defined as
the rate of change of velocity
A rocket can fly into space because:
the rocket pushes on exhaust gases and the exhaust gases push back on the rocket
A stone is thrown horizontally from the top of a tower at the same instant a ball is dropped vertically. Which object is traveling faster when it hits the level ground below?
the stone
The speeds of the planets about the sun depend on
their distances from the sun
The magnitude of the gravitational force acting on an object is
weight
The area under the curve, on a Force versus position (F vs. x) graph, represents
work
In the graph above, a toy car rolls from +3 m to +5 m. Which of the following statements is true?
xi = +3 m
If you run a complete loop around an outdoor track (400 m), in 100 s, your average velocity is
zero
The displacement x of an object moving along the x-axis is shown above as a function of time t. The acceleration of this object must be
zero
If you walk 5.0 m horizontally forward at a constant velocity carrying a 10-N object, the amount of work you do is
zero.
An object starting from rest begins to rotate with constant angular acceleration á. In a time t the object rotates through an angle è. Through what angle did the object rotate in the time t/3?
θ/9
The conservation of momentum is most closely related to
Newton's 3rd law
A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of
1 kg m/s.
A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of
1 unit
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is
10 times as much
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
In an elastic collision, if the momentum is conserved, then which of the following statements is true about kinetic energy?
Kinetic energy is also conserved
In an inelastic collision, if the momentum is conserved, then which of the following statements is true about kinetic energy?
Kinetic energy is lost
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
The impulse-momentum relationship is a direct result of
Newton's 2nd law
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 has the largest momentum relative to the Earth's surface?
a pickup truck speeding along a highway
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
When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. In this way the average force your body experiences is
about 1/10 as great
Hang from a pair of gym rings and the upward support forces of the rings will always
add up to equal your weight
A car traveling along the highway needs a certain amount of force exerted on it to stop it in a certain distance. More stopping force is required when the car has
all of these
An object in mechanical equilibrium is an object
all of these
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the
arrow's push against the bowstring
You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact?
both the same
If no external forces are acting on a moving object, it will
continue moving at the same velocity
A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is
doubled
According to the impulse-momentum equation Ft = change in (mv), a person will suffer less injury falling on a wooden floor which "gives" than on a more rigid cement floor. The "F" in the above equation stands for the force exerted on the
either the force on the person or the force on the floor
In a game of pool, the white cue ball hits the #5 ball and stops, while the #5 ball moves away with the same velocity as the cue ball had originally. The type of collision is
elastic
A karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force experienced by her hand is
identical to the force applied to the block
A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun
if the mass of the bullet equals the mass of the gun
Air bags reduce injury in automobile accidents by:
increasing the time of collision
When you are in the way of a fast-moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a
long time
Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has a greater
momentum
In a two-body collision,
momentum is always conserved
When a cannon fires a cannonball, the cannon will recoil backward because the
momentum of the cannonball and cannon is conserved
In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the
moon
If a monkey floating in outer space throws his hat away, the hat and the monkey will both
move away from each other, but at different speeds
An astronaut , floating alone in outer space, throws a baseball. If the ball floats away at a speed of 20 meters per second, the astronaut will
move in the opposite direction, but at a lower speed
A plane, flying horizontally, releases a bomb, which explodes before hitting the ground. Neglecting air resistance, the center of mass of the bomb fragments, just after the explosion
moves along a parabolic path
To calculate momentum:
multiply the mass of an object by its velocity.
A skydiver falls towards the Earth. The attraction of the Earth on the diver pulls the diver down. What is the reaction to this force?
none of these
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same
none of these
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
It is correct to say that impulse is equal to
the change in momentum it produces
A 100-kg football linebacker moving at 2.0 m/s east tackles head-on an 80-kg halfback running 3.0 m/s west. Neglecting the effects due to digging in of cleats,
the halfback will drive the linebacker backward
A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass?
the one on the moon
The change in an object's momentum is equal to
the product of the force applied to the object and the time interval
Compared to the mass of a certain object on Earth, the mass of the same object on the moon is
the same
Suppose that a tiny gun made of a strong but very light material fires a bullet that is more massive than the gun itself. For such a weapon
the target would be safer than the shooter
Kiki accidentally nudges a glass tumbler with her elbow and it falls toward a hard, ceramic tile floor. As a soccer player, Kiki reacts by catching the glass with her foot and lowering it to the floor, preventing the glass from breaking. Her action prevents the breakage because:
the time interval for stopping is greater when Kiki catches the glass with her foot
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
As an object falls toward Earth,
the upward acceleration of Earth is negligible because of its large mass
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
