Physics Final: Multiple Choice

An ideal gas is compressed in a well-insulated chamber using a well-insulated piston. This process is: - isobaric. - isothermal. - isochoric. - adiabatic.

Adiabatic

Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any significant air resistance. Compare the time it takes each of them to reach the lake below: - Alice reaches the surface of the lake first. - Alice and Tom will reach the surface of the lake at the same time. - Tom reaches the surface of the lake first.

Alice and Tom will reach the surface of the lake at the same time.

When a rigid body rotates about a fixed axis, all the points in the body have the same: - angular acceleration. - linear displacement. - centripetal acceleration. - tangential acceleration. - tangential speed.

Angular acceleration.

In a resonating pipe that is open at both ends, there: - is a displacement node at one end and a displacement anti-node at the other end. - are displacement nodes at each end. - are displacement anti-nodes at each end. - None of the above are possible.

Are displacement anti-nodes at each end.

A ball is released from rest on a no-slip surface, as shown in the figure. After reaching its lowest point, the ball begins to rise again, this time on a frictionless surface as shown in the figure. When the ball reaches its maximum height on the frictionless surface, it is: - at a lesser height as when it was released. - at a greater height as when it was released. - at the same height as when it was released. - It is impossible to tell without knowing the mass of the ball. - It is impossible to tell without knowing the radius of the ball.

At a lesser height as when it was released.

Block 1 and block 2 have the same mass, m, and are released from the top of two inclined planes of the same height making 30° and 60° angles with the horizontal direction, respectively. If the coefficient of friction is the same in both cases, which of the blocks is going faster when it reaches the bottom of its respective incline? - Both blocks have the same speed at the bottom. - We must know the actual masses of the blocks to answer. - Block 1 is faster. - Block 2 is faster. - There is not enough information to answer the question because we do not know the value of the coefficient of kinetic friction.

Block 2 is faster.

You are driving a late model convertible car at the 65 mph speed limit with its soft flexible roof closed up and the windows closed. You observe that the roof: - bows inward only when you are driving downhill. - bows inward. - bows inward only when you are driving uphill. - is no different from when the car was at rest. - bows outward.

Bows outward.

You are standing on a skateboard, initially at rest. A friend throws a very heavy ball towards you. You can either catch the object or deflect the object back towards your friend (such that it moves away from you with the same speed as it was originally thrown). What should you do in order to MINIMIZE your speed on the skateboard? - Deflect the ball. - Catch the ball. - Your final speed on the skateboard will be the same regardless whether you catch the ball or deflect the ball.

Catch the ball.

As the speed of a moving fluid increases, the pressure in the fluid: - may increase or decrease, depending on the density of the fluid. - remains constant. - decreases. - increases.

Decreases.

If we double only the mass of a vibrating ideal mass-and-spring system, the mechanical energy of the system: - does not change. - increases by a factor of 2. - increases by a factor of 3. - increases by a factor of √(2). - increases by a factor of 4

Does not change.

A dog is standing in the bed of a pickup truck. The bed is coated with ice, causing the force of friction between the dog and the truck to be zero. The truck is initially at rest, and then accelerates to the right, moving along a flat road. As seen from a stationary observer (watching the truck move to the right), the dog: - moves to the left, as the truck moves to the right, causing the dog to slide towards the back of the truck. - does not move left or right, but the back of the truck moves towards the dog. - moves to the right at the same rate as the truck, so it doesn't slide. - moves to the right, but not as quickly as the truck is moving to the right, causing it to slide towards the back of the truck.

Does not move left or right, but the back of the truck moves towards the dog.

You swing a bat and hit a heavy box with a force of 1500 N. The force the box exerts on the bat is: - exactly 1500 N only if the box does not move. - exactly 1500 N whether or not the box moves. - less than 1500 N if the box moves. - greater than 1500 N if the box moves. - greater than 1500 N if the bat bounces back.

Exactly 1500 N, whether or not the box moves.

If you swing a bucket of water fast enough in a vertical circle, at the highest point the water does not spill out because an outward force balances the pull of gravity on the water. - True - False

False

In order to get an object moving, you must push harder on it than it pushes back on you. - True - False

False

A frictionless pendulum released from 65 degrees with the vertical will vibrate with the same frequency as if it were released from 5 degrees with the vertical because the period is independent of the amplitude and mass. - True - False

False.

A plane flies toward a stationary siren at 1/4 the speed of sound. Then the plane stands still on the ground and the siren is driven toward it at 1/4 the speed of sound. In both cases, a person sitting in the plane will hear the same frequency of sound from the siren. - True - False

False.

If two forces of equal magnitude act on an object that is hinged at a pivot, the force acting farther from the pivot must produce the greater torque about the pivot. - unable to decide without knowing the shape of the object - true - false

False.

If two vectors are perpendicular to each other, their cross product must be zero. - True - False

False.

The entropy of an isolated system must be conserved, so it never changes. - True - False

False.

There must be equal amounts of mass on both side of the center of mass of an object. - True - False

False.

Water flows through a pipe having a varying width. More water flows per second through the wide section than through the narrow section because there is more room for it to flow. - True - False

False.

When a vapor condenses: - heat energy leaves the substance. - the temperature of the substance increases. - heat energy enters the substance. - the temperature of the substance decreases.

Heat energy leaves the substance.

If we double only the spring constant of a vibrating ideal mass-and-spring system, the mechanical energy of the system: - increases by a factor of 4. - increases by a factor of 2. - increases by a factor of 3. - does not change. - increases by a factor of √(2).

Increase by a factor of 2.

When an ideal gas increases in volume at constant pressure, the average kinetic energy of the gas molecules: - does not change. - increases. - may or may not change, but insufficient information is given to make such a determination. - may either increase or decrease, depending on whether or not the process is carried out adiabatically. - decreases

Increases.

A very small round ball is located near a large solid sphere of uniform density. The force that the large sphere exerts on the ball: - is independent of the mass of the sphere. - can only be calculated using calculus. - is exactly the same as it would be if all the mass of the sphere were concentrated at the center of the sphere. - is independent of the mass of the ball. - is approximately the same as it would be if all the mass of the sphere were concentrated at the center of the sphere.

Is exactly the same as it would be if all the mass of the sphere were concentrated at the center of the sphere.

The number of molecules in one mole of a substance: - is the same for all substances. - depends on the atomic weight of the substance. - depends on the molecular weight of the substance. - depends on the density of the substance. - depends on the temperature of the substance.

Is the same for all substances.

A sample of an ideal gas is slowly compressed to one-half its original volume with no change in temperature. What happens to the average speed of the molecules in the sample? - It becomes 1/2 as great. - It does not change. - It becomes 4 times as great. - It becomes 1/4 as great. - It becomes 2 times as great.

It does not change.

When a fixed amount of ideal gas goes through an isothermal expansion: - its temperature must decrease. - no heat enters or leaves the gas. - the gas does no work. - its pressure must increase. - its internal (thermal) energy does not change.

Its internal (thermal) energy does not change.

A mass is pressed against (but is not attached to) an ideal horizontal spring on a frictionless horizontal surface. After being released from rest, the mass acquires a maximum speed v and a maximum kinetic energy K. If instead the mass initially compresses the spring twice as far: - Its maximum speed will be 4v and its maximum kinetic energy will be 2K. - Its maximum speed will be 2v and its maximum kinetic energy will be 2K. - Its maximum speed will be 2v and its maximum kinetic energy will be 4K. - Its maximum speed will be 2v and its maximum kinetic energy will be k√(2). - Its maximum speed will be v√(2) and its maximum kinetic energy will be 2K

Its maximum speed will be v√(2) and its maximum kinetic energy will be 2K.

A baseball is thrown vertically upward and feels no air resistance. As it is rising: - both its momentum and its mechanical energy are conserved. - both its momentum and its kinetic energy are conserved. - its kinetic energy is conserved, but its momentum is not conserved. - its gravitational potential energy is not conserved, buts its momentum is conserved. - its momentum is not conserved, but its mechanical energy is conserved.

Its momentum is not conserved, but its mechanical energy is conserved.

Consider a uniform solid sphere of radius R and mass M, rolling without slipping. Which form of its kinetic energy is larger, translational or rotational? - Its rotational kinetic energy is larger than its translational kinetic energy. - Its translational kinetic energy is larger than its rotational kinetic energy. - Both forms of energy are equal. - You need to know the speed of the sphere to tell.

Its translational kinetic energy is larger than its rotational kinetic energy.

On a smooth horizontal floor, an object slides into a spring which is attached to another mass that is initially stationary. When the spring is most compressed, both objects are moving at the same speed. Ignoring friction, what is conserved during this interaction? - momentum and potential energy - momentum and mechanical energy - momentum only - kinetic energy only - momentum and kinetic energy

Momentum and Mechanical Energy

As a result of any natural process, the total entropy of any system plus that of its environment: - never increases. - never decreases. - always stays the same. - sometimes decreases.

Never decreases.

When a gas undergoes an isothermal process, there is: - no change in the volume of the gas. - no work done by (or on) the gas. - no heat added to the gas. - no change in the temperature of the gas. - no change in the pressure of the gas.

No change in the temperature of the gas.

When a fixed amount of ideal gas goes through an adiabatic expansion: - the gas does no work. - its pressure must increase. - no heat enters or leaves the gas. - its temperature cannot change. - its internal (thermal) energy does not change.

No heat enters or leaves.

If you double the pressure on the surface of a can of water, the buoyant force on a stone placed in that water will: - double. - not change. - increase, but not double. - decrease, but not by one-half.

Not change.

A heavy boy and a lightweight girl are balanced on a massless seesaw. If they both move forward so that they are one-half their original distance from the pivot point, what will happen to the seesaw? Assume that both people are small enough compared to the length of the seesaw to be thought of as point masses. - It is impossible to say without knowing the distances. - Nothing will happen; the seesaw will still be balanced. - It is impossible to say without knowing the masses. - The side the boy is sitting on will tilt downward. - The side the girl is sitting on will tilt downward.

Nothing will happen; the seesaw will still be balanced.

Two objects are dropped from a bridge, an interval of 1.0 s apart, and experience no appreciable air resistance. As time progresses, the DIFFERENCE in their speeds: - increases. - decreases at first, but then stays constant. - remains constant. - increases at first, but then stays constant. - decreases.

Remains constant.

A uniform disk, a uniform hoop, and a uniform solid sphere are released at the same time at the top of an inclined ramp. They all roll without slipping. In what order do they reach the bottom of the ramp? - hoop, disk, sphere - disk, hoop, sphere - sphere, hoop, disk - hoop, sphere, disk - sphere, disk, hoop

Sphere, disk, hoop.

A ball is thrown directly upward and experiences no air resistance. Which one of the following statements about its motion is correct? - The acceleration is downward during the entire time the ball is in the air. - The acceleration of the ball is downward while it is traveling up and downward while it is traveling down but is zero at the highest point when the ball stops. - The acceleration of the ball is downward while it is traveling up and upward while it is traveling down. - The acceleration of the ball is upward while it is traveling up and downward while it is traveling down.

The acceleration is downward during the entire time the ball is in the air.

An engine manufacturer makes the claim that the engine they have developed will, on each cycle, take 100 J of heat out of boiling water at 100°C, do mechanical work of 80 J, and exhaust 20 J of heat at 10°C. What, if anything, is wrong with this claim? - There is nothing wrong with this claim because 100 J = 20 J + 80 J. - The heat exhausted must always be greater than the work done according to the second law of thermodynamics. - The efficiency of this engine is greater than the ideal Carnot cycle efficiency. - An engine would operate by taking in heat at the lower temperature and exhausting heat at the higher temperature. - This engine violates the first law of thermodynamics because 100 J + 20 J ≠ 80 J

The efficiency of this engine is greater than the ideal Carnot cycle efficiency.

Consider two less-than-desirable options: In the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. In the second option you are driving 30 mph and crash head-on into a stationary brick wall. In neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. Which of these two situations would result in the greatest impact force? - Hitting the brick wall - Hitting the other car - The force would be the same in both cases. - We cannot answer this question without more information. - None of these is true.

The force would be the same in both cases.

When a fixed amount of ideal gas goes through an isochoric process: - its temperature must increase. - its pressure must increase. - the gas does no work. - its internal (thermal) energy does not change. - no heat enters or leaves the gas.

The gas does no work.

A frictionless pendulum clock on the surface of the earth has a period of 1.00 s. On a distant planet, the length of the pendulum must be shortened slightly to have a period of 1.00 s. What is true about the acceleration due to gravity on the distant planet? - The gravitational acceleration on the planet is slightly greater than g. - We cannot tell because we do not know the mass of the pendulum. - The gravitational acceleration on the planet is slightly less than g. - The gravitational acceleration on the planet is equal to g.

The gravitational acceleration on the planet is slightly less than g.

Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. When they hit the ground: - the heavier one will have four times the kinetic energy of the lighter one. - the heavier one will have twice the kinetic energy of the lighter one. - both of them will have the same kinetic energy. - the heavier one will have √(2) times the kinetic energy of the lighter one.

The heavier one will have twice the kinetic energy of the lighter one.

A container is filled with a mixture of helium (light molecules) and oxygen (heavy molecules) gases. A thermometer in the reads 22°C. Which gas molecules have the greater average speed? - The oxygen molecules do because they are more massive. - The oxygen molecules do because they are diatomic. - The helium molecules do because they are less massive. - It is the same for both of the gases because the temperatures are the same. - The helium molecules do because they are monatomic.

The helium molecules do because they are less massive.

While an object is in projectile motion (with upward being positive) with no air resistance: - the horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to -g. - the vertical component of its velocity remains constant and the vertical component of its acceleration is equal to -g. - the horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to zero. - the vertical component of both its velocity and its acceleration remain constant. - the horizontal component of its velocity remains constant and the horizontal component of its acceleration is equal to -g.

The horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to -g.

A 50-cm3 block of wood is floating partially submerged in water, and a 50-cm3 block of iron is totally submerged in water. Which block has the greater buoyant force on it? - the iron - the wood - Both have the same buoyant force. - The answer cannot be determined without knowing the densities of the blocks.

The iron.

A 1.0-kg block and a 2.0-kg block are pressed together on a horizontal frictionless surface with a compressed very light spring between them. They are not attached to the spring. After they are released and have both moved free of the spring: - the lighter block will have more kinetic energy than the heavier block. - the heavier block will have more kinetic energy than the lighter block. - both blocks will have equal speeds. - the magnitude of the momentum of the heavier block will be greater than the magnitude of the momentum of the lighter block. - both blocks will both have the same amount of kinetic energy

The lighter block will have more kinetic energy than the heavier block.

In simple harmonic motion, the speed is greatest at that point in the cycle when: - the potential energy is a maximum. - the magnitude of the acceleration is a minimum. - the kinetic energy is a minimum. - the magnitude of the acceleration is a maximum. - the displacement is a maximum.

The magnitude of the acceleration is a minimum.

In an INELASTIC collision between two objects: - the momentum of the system is conserved but the kinetic energy of the system is not conserved. - the momentum of each object is conserved. - both the momentum and the kinetic energy of the system are conserved. - the kinetic energy of the system is conserved, but the momentum of the system is not conserved. - the kinetic energy of each object is conserved.

The momentum of the system is conserved, but the kinetic energy of the system is not conserved.

In designing buildings to be erected in an area prone to earthquakes, what relationship should the designer try to achieve between the natural frequency of the building and the typical earthquake frequencies? - The natural frequency of the building should be very different from typical earthquake frequencies. - The natural frequency of the building should be exactly the same as typical earthquake frequencies. - The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly higher. - The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly lower.

The natural frequency of the building should be very different from typical earthquake frequencies.

An object is moving forward with a constant velocity. Which statement about this object MUST be true? - The net force on the object is in the forward direction. - The acceleration of the object is in the forward direction. - The net force on the object is zero. - No forces are acting on the object.

The net force on the object is zero.

If the torque on an object adds up to zero: - the object cannot be turning. - the object is at rest. - the object could be accelerating linearly, but it could not be turning. - the forces on it also add up to zero. - the object could be both turning and accelerating linearly.

The object could be both turning and accelerating linearly.

A wave pulse traveling to the right along a thin cord reaches a discontinuity where the rope becomes thicker and heavier. What is the orientation of the reflected and transmitted pulses? - The reflected pulse returns inverted while the transmitted pulse is right side up. - Both pulses are inverted. - The reflected pulse returns right side up while the transmitted pulse is inverted. - Both pulses are right side up.

The reflected pulse returns inverted, while the transmitted pulse is right side up.

A mole of oxygen (O2) molecules and a mole of carbon dioxide (CO2) molecules at the same temperature and pressure have: - the same average molecular speeds. - the same number of molecules. - different volumes. - the same number of atoms. - different average kinetic energy per molecule

The same number of molecules.

If the temperature of a fixed amount of an ideal gas is increased, it NECESSARILY follows that: - the speed of the gas molecules will increase. - the volume of the gas will increase. - the pressure of the gas will increase. - All of the above statements are correct

The speed of the gas molecules will increase.

When a fixed amount of ideal gas goes through an isobaric expansion: - its pressure must increase. - its internal (thermal) energy does not change. - no heat enters or leaves the gas. - its temperature must increase. - the gas does no work.

The temperature must increase.

A cup of water containing an ice cube at 0°C is filled to the brim. The tip of the ice cube sticks out of the surface. As the ice melts, you observe that: - the water level remains the same. - the water level actually goes down. - the cup might overflow but it depends on the actual mass of the ice cube. - the cup overflows. - There is not enough information to answer this question.

The water level remains the same.

Shock waves occur when: - the period of the waves matches the lifetime of the waves. - the frequency of the waves is the resonant frequency of the system. - two waves from different sources collide with each other. - the wave source is traveling at a speed greater than the wave speed. - the amplitude of waves exceeds the critical shock value.

The wave source is traveling at a speed greater than the wave speed.

For an object in uniform circular motion, its velocity and acceleration vectors are always perpendicular to each other at every point in the path. - True - False

True

If the dot product of two nonzero vectors is zero, the vectors must be perpendicular to each other. - True - False

True

When an object is solely under the influence of conservative forces, the sum of its kinetic and potential energies does not change. - True - False

True.

The angular momentum of a system remains constant: - when the total kinetic energy is constant. - when no torque acts on the system. - when no net external force acts on the system. - all the time since it is a conserved quantity. - when the linear momentum and the energy are constant.

When no torque acts on the system.

Is it possible to transfer heat from a cold reservoir to a hot reservoir? - Yes; this will happen naturally. - Theoretically yes, but it hasn't been accomplished yet. - Yes, but work will have to be done. - No; this is forbidden by the second law of thermodynamics

Yes, but work will have to be done.

Is it possible to transfer heat from a hot reservoir to a cold reservoir? - Theoretically yes, but it hasn't been accomplished yet. - Yes; this will happen naturally. - No; this is forbidden by the second law of thermodynamics. - Yes, but work will have to be done.

Yes, this will happen naturally.

A 615 N student standing on a scale in an elevator notices that the scale reads 645 N. From this information, the student knows that the elevator must be moving: - downward. - upward. - You cannot tell if it is moving upward or downward.

You cannot tell if it is moving upward of downward.

A stalled car is being pushed up a hill at constant velocity by three people. The net force on the car is: - down the hill and greater than the weight of the car. - down the hill and equal to the weight of the car. - zero. - up the hill and greater than the weight of the car. - up the hill and equal to the weight of the car.

Zero.