Physics 1
The ballistics pendulum shown is used to determine the velocity of a bullet. The value of v' can be calculated using the following equation
(2GH)1/2
The only way that a heat engine can have an efficiency of 1, is if the engine's cold temperature is
0
Carly places one end of a steel bar in a Bunsen flame and the other end in an ice cube. By what factor is the rate of heat flow changed when the bar's cross-sectional area is doubled?
2
Three equal masses collide as shown Which of the following statements is true 1.The magnitude of v2 is greater than the magnitude of v3. 2.The magnitude of v3 is greater than the magnitude of v2. 3. The magnitudes of v2, and v3 are equal. 4.The magnitudes of v1, v2, and v3 are all equal
2
Perpetual motion machines of the second kind are not allowed by the
2nd law of thermodynimics
A car is traveling in a circle on a flat road. It's speedometer reads a constant 50 mph at all times. Which of the following is correct. 1.The velocity of the car is constant. 2.None of the other answers are correct. 3.The speed of the car is constant. 4.The acceleration of the car is constant.
3
1 Calorie of food is equal to which of the following?
4186 J
If an object scaled up by a factor of 3 (s = 3), the rate of heat loss from the surface of the object increases by a factor of
9
When considering human metabolism in terms of the 1st Law of Thermodynamics, which of the following represents the metabolic rate?
DU / Dt
Accuracy of a measurement is determined by the number of decimal places. 1.T 2.F
F
Angular acceleration and centripetal acceleration are the same. 1.T 2.F
F
If the speed of a car is doubled, its stopping distance will be doubled. 1.T 2.F
F
If the speed of an object is doubled, its kinetic energy will be doubled 1.T 2.F
F
In Newton's Third Law the "action" and "reaction" are on the same object 1.T 2.F
F
Increasing the impact time in a collision increases the impact force. 1.T 2.F
F
Most objects in the universe are moving at constant velocity. 1.T 2.F
F
Newton's Second Law states that any force acting on any mass will produce an acceleration. 1.T 2.F
F
The acceleration of gravity is the same everywhere in the universe 1.T 2.F
F
The amount of drag on an object decreases as its speed increases. 1.T 2.F
F
The constant "G" in Newton's Universal Law of Gravitation is 9.8 m/s2. 1.T 2.F
F
The escape velocity from the Earth is infinite. 1.T 2.F
F
The moment of inertia of a disk is greater than the moment of inertia of a ring. 1.T 2.F
F
The moment of inertia of an object is a vector. 1.T 2.F
F
The weight of an object is the same on the Moon as on the Earth 1.T 2.F
F
Andrea and Chuck are riding on a merry-go-round. Andrea rides on a horse at the outer rim of the circular platform, twice as far from the center of the circular platform as Chuck, who rides on an inner horse. Chuck's translational speed is
HALF of andreas
If global warming continues, it's likely that some ice from the polar ice caps of the Earth will melt and the water will be distributed closer to the Equator. If this occurs, would the length of the day (one revolution) 1.increase 2.decrease 3.remain the same
Increase
Which of the following involves the greatest heat transfer?
One gram of steam at 100oC changing to water at 100oC.
A 400 g mass, m1, is balanced at the end of a 100,g meter stick as shown. If r1 is increased, the system rotates counterclockwise. Assume the center of mass of the meter stick is at the 50 cm mark and m1 is at the 0 cm mark. The clockwise torque is supplied by the meter stick.
T
A watt is a unit of energy 1.T 2.F
T
An object can be moving at constant speed and still be accelerating. 1.T 2.F
T
An object is in rotational equilibrium when the net torque on the object is zero 1.T 2.F
T
Angular velocity is a vector 1.T 2.F
T
Distance is a scalar while displacement is a vector 1.T 2.F
T
If the distance between 2 masses is tripled, the force of gravity between the masses will be one ninth as great. 1.T 2.F
T
In an elastic collision the maximum impact force is approximately equal to twice the average impact force. 1.T 2.F
T
In dealing with free fall up is positive and down is negative 1.T 2.F
T
Kinetic energy is conserved in elastic but not in inelastic collisions. 1.T 2.F
T
Momentum is a vector but kinetic energy is a scalar 1.T 2.F
T
Momentum is conserved in both elastic and inelastic collisions. 1.T 2.F
T
Most people have a reaction time of more than .13 seconds 1.T 2.F
T
The acceleration of an object is 0 if the net force on it is 0. 1.T 2.F
T
The coefficient of friction is an empirical number not an inherent property of a material. 1.T 2.F
T
The coefficient of static friction (µs) is never less than the coefficient of kinetic friction (µk). 1.T 2.F
T
The force of friction increases as the Normal force increases 1.T 2.F
T
The inertia of an object is the same on the Moon as on the Earth. 1.T 2.F
T
The mass of an object is a quantitative measure of its inertia. 1.T 2.F
T
Three equal masses collide as shown This was an elastic collision. 1.T 2.F
T
Andrea and Chuck are riding on a merry-go-round. Andrea rides on a horse at the outer rim of the circular platform, twice as far from the center of the circular platform as Chuck, who rides on an inner horse. When the merry-go-round is rotating at a constant angular speed, Chuck's's angular speed is
THE SAM EAS ANDREAS
The reason for the answer to #35 is primarily due to the fact that 1.the moments of inertia of all are the same. 2.the moment of inertia of the disk is least. 3. the moment of inertia of the ball is least. 4. the moment of inertia of the ring is least
The moment of inertia of the ball is least
Which of the following produces greenhouse gases?
all
What is the mathematical relationship between the coefficient of volume expansion, b, for given material and its corresponding coefficient of linear expansion, a?
b=3a
The answer to #38 is based on the fact(s) that
both
The maximum theoretical thermodynamic efficiency of a heat engine operating between hot and cold reservoirs is a function of which of the following?
both
You can increase the Torque applied by a wrench by
both increasing the length of the wrench and increasing the force on the wrench
An object moves in a circular path with constant speed v. Which of the following statements is true?
both velocity & acceleration are changing
According to the second law of thermodynamics, which of the following applies to the heat received from a high temperature reservoir by a heat engine operating in a complete cycle?
cannot be completely converted to work
What happens to a given mass of water as it is heated from 2oC to 4oC?
contract
Heat is transferred from the equator to the polar regions primarily by
convection
Which one of the following processes of heat transfer requires the presence of a fluid?
convection
A bimetallic strip made of steel and copper bends toward the steel because
copper has a greater coefficient of linear expansion than steel.
A student is rotating at a constant angular velocity while holding two weights as shown. If the weights are moved outward, the angular velocity will #38 1.same 2.decrease 3.increase
decrease
Entropy is a measure of the ___________ of a system.
disorder
Which of the following choices best corresponds to what is required by the second law of thermodynamics for any process taking place in an isolated system?
entropy increase
For the answer to #35 to be correct, all three must have the same mass. 1.t 2.f
f
Motion in which gravity is the only force acting is called
free fall
Evaporation cools the liquid that is left behind because the molecules that leave the liquid during evaporation:
greater average speed
Physics tries to answer the question: ______ does the universe work
how
A steel plate has a hole drilled through it. The plate is put into a furnace and heated. What happens to the size of the inside diameter of a hole as its temperature increases
increasing
The stability of an object can be increased by __ the size of the base. 1.increase 2.decrease 3.neither
increasing
According to the first law of thermodynamics, the sum of the heat gained by a system and the work done on that same system is equivalent to which of the following?
internal energy change
The ballistics pendulum shown is used to determine the velocity of a bullet. Which of the following is not true.
kEA=KEA
The absolute temperature of an ideal gas is directly proportional to which of the following properties, when taken as an average, of the molecules of that gas?
kenetic energy
A cart of mass 2.0 kg, moving at a constant velocity of 6.0 m/s collides head on with a stationary 1.0 kg cart. The two carts stick together and move off in a straight line at velocity v'. The total kinetic energy of the system after the collision was ___ before the collision . 1.less than 2.greater than
less than
The stability of an object can be increased by __ the center of mass. 1.raising 2.lowering 3.neither
lowering
Which of the following statements is true?
object do not contain heat
During an isobaric process which one of the following does not change?
pressure
How does the heat energy from the sun reach us through the vacuum of space?
radiation
If one's hands are being warmed by holding them to one side of a flame, the predominant form of heat transfer is what process?
radiation
Which type of heating causes sunburn?
radiation
50 grams of a solid at 50°C is place in 100 grams of a fluid at 20°C. Thermal equilibrium is reached at 30°C. The specific heat of the solid:
same as the fluid
What property of objects that is most used to measure temperature
solids, liquids, and gases usually expand when heated.
On a sunny day at the beach, the reason the sand gets so hot and the water stays relatively cool is attributed to the difference in which property between water and sand?
specific heat
Heat flow occurs between two bodies in thermal contact when they differ in what property?
temp
A solid ball, a disk, and a ring all roll down an incline as shown. Assume that all start from rest from the same starting point on the incline. The one that reaches the bottom first is #35 1.the ball 2.they arrive together 3.the disk 4.the ring
the ball
A hockey puck B rests on a smooth ice surface and is struck by a second puck A moving at 30.0 m/s. Both move off at angles of 45o with the original direction of A. The pucks have equalmasses of .200 kg each. The direction of the total momentum of the system after the collision was 1.to the lest 2.to the right
to the right
The center of mass of an object can be inside or outside the object. 1.t 2.f
true
In cloud formation, water vapor turns into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to:
warmer