Conceptual Physics Test 5-7

Inside a freely falling elevator, there would be no A) gravitational force on you B) apparent weight for you C) both of these D) none of these

B) apparent weight for you

When a rifle is fired, it recoils as the bullet is set in motion. The rifle and bullet ideally acquire equal A) amounts of kinetic energy. B) but opposite amounts of momentum. C) neither of these D) both of these

B) but opposite amounts of momentum.

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is A) smaller. B) greater. C) the same.

B) greater.

When an automobile is braked to a stop, its kinetic energy is transformed to A) potential energy. B) heat. C) energy of rest. D) energy of motion. E) stopping energy.

B) heat.

If you push an object twice as far while applying the same force, you do A) four times as much work. B) half as much work. C) twice as much work. D) the same amount of work.

C) twice as much work.

A black hole is A) simply the remains of a giant star or stars that have undergone gravitational collapse B) much more massive than stars C) a small region that contains the mass of many galaxies

A

If the speed of a moving object doubles, which of the following also doubles? A) momentum B) kinetic energy C) acceleration D) all of the above

A

Padded dashboards in cars are safer in an accident than non-padded ones because an occupant hitting the dash has A) increased time of impact. B) decreased time of impact. C) decreased impulse. D) increased momentum.

A

Whereas impulse involves the time that a force acts, work involves the A) distance that a force acts B) time and distance that a force acts C) acceleration that a force produces

A

What is the force of gravity on a 500-newton woman standing on the Earth's surface? A) 500 N B) 250 N C) 5000 N D) 50 N

A) 500 N

How far must one travel to get away from the Earth's gravitational field? A) Forget it; you can't travel far enough. B) to a region above the Earth's atmosphere C) to a region well beyond the moon D) to a region beyond the solar system

A) Forget it; you can't travel far enough.

A moving object has A) all of these B) velocity. C) energy. D) speed. E) momentum.

A) all of these

The Earth's gravitational field extends A) both inside and outside the Earth and throughout the entire universe. B) only above and beyond the Earth's surface and cancels inside the Earth C) neither of these

A) both inside and outside the Earth and throughout the entire universe.

When bullets are fired from an airplane in the forward direction, the momentum of the airplane will be A) decreased. B) increased C) unchanged.

A) decreased.

According to Newton, doubling the distance between two interacting objects A) divides by 4 the gravitational force between them. B) multiplies by 2 the gravitational force between them. C) divides by 2 the gravitational force between them. D) multiplies by 4 the gravitational force between them.

A) divides by 4 the gravitational force between them.

A clerk can lift containers a vertical distance of 1 meter or can roll them up a 2 meter-long ramp to the same elevation. With the ramp, the applied force required is about A) half as much. B) the same. C) twice as much. D) four times as much.

A) half as much.

An object may have potential energy because of its A) location. B) none of these C) acceleration. D) speed. E) momentum.

A) location.

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 A) long time. B) same way either way C) short time.

A) long time.

An object that has kinetic energy must be A) moving. B) none of these C) at an elevated position. D) at rest. E) falling.

A) moving.

When a star collapses to form a black hole, its mass A) remains the same. B) decreases. C) increases.

A) remains the same.

After rolling halfway down an incline, a marble's kinetic energy is A) the same as its potential energy B) impossible to determine C) greater than its potential energy D) less than its potential energy

A) the same as its potential energy

Strictly speaking, more fuel is consumed by your car if an air conditioner, headlights, or even a radio is turned on. This statement is A) true. B) true only if the car's engine is running fast. C) true only if the car's engine is running slowly. D) totally false.

A) true.

According to Newton, the greater the masses of interacting objects, the A) less the gravitational force between them B) greater the gravitational force between them C) greater the force between them by the square of the masses

B

It is correct to say that impulse is equal to A) momentum. B) the change in momentum. C) the force multiplied by the distance the force acts. D) velocity multiplied by time

B

Newton discovered A) gravity B) that gravity is universal C) neither

B

The difference between impulse and impact force involves the A) distance the force acts. B) time the force acts. C) difference between acceleration and velocity. D) mass and its effect on resisting a change in momentum.

B

If 50 joules of energy compresses a spring and the spring shoots a ball that has 40 joules of kinetic energy, A) 10 joules go to warming the spot where the ball lands. B) 10 joules go to warming the spring. C) none of these D) 10 joules are destroyed due to heat. E) energy is not conserved.

B) 10 joules go to warming the spring.

A TV set is pushed a distance of 2 m with a force of 20 N. How much work is done on the set? A) 10 J B) 40 J C) 800 J D) 2 J E) 20 J

B) 40 J

The concept of force is not fundamental to A) Newton's theory of gravitation. B) Einstein's theory of gravitation. C) both of these D) neither of these

B) Einstein's theory of gravitation.

The direction of a gravitational field is A) opposite to the direction of gravitational attraction. B) in the same direction as the gravitational attraction. C) away from the center of gravity of an object.

B) in the same direction as the gravitational attraction.

The best time for digging clams (when the low tide is extra low) is during the time of the A) none of these times in particular B) new or full moon. C) half moon. D) quarter moon.

B) new or full moon.

If you push for a half hour or a whole hour against a stationary wall A) it is impossible to determine how much work is done. B) no work on the wall is done in either case. C) half as much work is done during the half hour. D) twice as much work is done during the half hour.

B) no work on the wall is done in either case.

An asteroid exerts a 360-N gravitational force on a nearby spacecraft. This force is directed A) toward the sun. B) toward the asteroid. C) away from the asteroid.

B) toward the asteroid.

Compared to falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the A) carpeted floor provides a smaller impulse. B) stopping time is shorter on the carpet. C) stopping time is longer on the carpet. D) carpet provides a smaller impulse and a longer time.

C

The power required to exert 1 N force, over a distance of 1 m in 1 second is A) 2 W. B) 1/3 W. C) 1 W. D) 3 W.

C) 1 W.

When two objects interact, conservation of momentum is most closely related to A) Newton's 2nd law B) Newton's 1st law. C) Newton's 3rd law. D) Newton's 4th law

C) Newton's 3rd law.

Which of the following has the largest momentum relative to the Earth's surface? A) a dog running down the street B) a tightrope walker crossing Niagara Falls C) a pickup truck speeding along a highway D) the Science building on campus

C) a pickup truck speeding along a highway

An object lifted 10 meters gains 200 J of potential energy. If the same object is lifted 20 meters, its potential energy gain is A) four times as much. B) more than four times as much. C) twice as much D) half as much. E) the same.

C) twice as much

A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun A) because momentum is conserved. B) because velocity is conserved. C) because both velocity and momentum are conserved. D) if the mass of the bullet equals the mass of the gun. E) none of these

D

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 A) quadrupled B) unchanged C) zero D) doubled

D

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 A) more mass. B) more momentum. C) less stopping distance. D) all of these E) none of these

D) all of these

The reason the moon does not crash into the Earth is that the A) none of these B) moon has less mass than the Earth. C) gravitational pull of other planets keeps the moon up. D) moon has a sufficient tangential speed to keep it in orbit for a very long time. E) Earth's gravitational field is weak at the moon.

D) moon has a sufficient tangential speed to keep it in orbit for a very long time.

An object at rest may also have A) velocity. B) speed. C) momentum. D) potential energy. E) kinetic energy.

D) potential energy.

A ball rolling down an incline has its maximum kinetic energy at A) three-quarters of the way down. B) the top. C) halfway down. D) the bottom.

D) the bottom.

No work is done by gravity on a bowling ball that rolls along a bowling alley because A) no force acts on the ball. B) its kinetic energy remains constant. C) no potential energy is being converted to kinetic energy. D) the force on the ball is at right angles to the ball's motion. E) no distance is covered by the ball.

D) the force on the ball is at right angles to the ball's motion.

If you do work on an object in one-third the usual time, your power output is A) one third the usual power output. B) the usual power output. C) impossible to predict without additional information. D) three times the usual power output.

D) three times the usual power output.

If you push an object a given distance, while applying twice the force, you do A) four times as much work. B) the same amount of work. C) half as much work. D) twice as much work.

D) twice as much work.

If an object is raised twice as high, its potential energy will be A) half as much B) four times as much. C) impossible to determine unless the time is given. D) twice as much.

D) twice as much.

If an object has kinetic energy, then it must also have A) acceleration B) impulse C) force D) none of these E) momentum

E

The factor most directly responsible for making a black hole invisible is its A) rotation. B) none of these C) color. D) size. E) mass.

E) mass.

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 A) speed. B) acceleration. C) momentum. D) all of these E) none of these

E) none of these

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 A) conservation of energy would not hold. B) both conservation of energy and momentum would not hold. C) recoil problems would be lessened. D) conservation of momentum would not hold. E) the target would be safer than the shooter.

E) the target would be safer than the shooter.