Chapter 5 Energy Phy 2053 Conceptual Questions Phy 2053 Conceptual Questions.

Chapter 5Energy

Phy 2053 Conceptual Questions

Phy 2053ConceptualQuestions

If you push twice as hard against a stationary brick wall, the amount of work you do

A) doubles.

B) remains constant at zero.

C) remains constant but non-zero.

D) is cut in half.


Concept Questions 05-01/14

If you walk 5.0 m horizontally forward at a constant velocity carrying a 10 N object, the amount of work you do is

A) more than 50 J.

B) zero.

C) less than 50 J, but more than 0 J.

D) equal to 50 J.



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.

A) Work is + on the way up and + on the way down.

B) Work is + on the way up and - on the way down.

C) Work is - on the way up and + on the way down.

D) Work is - on the way up and - on the way down.



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?

A) All that can be said is that the truck has more kinetic energy.

B) The truck has twice the kinetic energy of the car.

C) The truck has 4 times the kinetic energy of the car.

D) The truck has 8 times the kinetic energy of the car.



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?

A) 1/2

B) 1/4

C) 2

D) 4



You slam on the brakes of your car in a panic, and skid a certain distance on a straight, level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?

A) It would have skidded 4 times farther.

B) It would have skidded twice as far.

C) It would have skidded 1.4 times farther.

D) It is impossible to tell from the information given.



Is it possible for a system to have negative potential energy?

A) Yes, as long as the total energy is positive.

B) Yes, since the choice of the zero of potential energy is arbitrary.

C) No, because the kinetic energy of a system must equal its potential energy.

D) No, because this would have no physical meaning.



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 initial potential energy of the second object compared to the first is

A) one-fourth as much.

B) one-half as much.

C) twice as much.

D) four times as much.



The total mechanical energy of a system

A) is equally divided between kinetic energy and potential energy.

B) is either all kinetic energy or all potential energy, at any one instant.

C) can never be negative.

D) is constant, only if conservative forces act.



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?

A) The heavy object, because it has greater kinetic energy.

B) They both slide to the same height.

C) The lightweight object, because it weighs less.

D) Cannot be determined from the information given.



The quantity is

A) the kinetic energy of the object.

B) the potential energy of the object.

C) the work done on the object by the force.

D) the power supplied to the object by the force.

tFd



What is the correct unit of power expressed in SI units?

A) kg m/s2

B) kg m2/s2

C) kg m2/s3

D) kg2 m/s2



Compared to yesterday, you did 3 times the work in one-third the time. To do so, your power output must have been

A) the same as yesterday's power output.

B) one-third of yesterday's power output.

C) 3 times yesterday's power output.

D) 9 times yesterday's power output.



Of the following, which is not a unit of power?

A) watt/second

B) newton-meter/second

C) joule/second

D) watt



Chapter 5 Energy Phy 2053 Conceptual Questions Phy 2053 Conceptual Questions.

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