Chpater 7 CQ

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

A. moving.

As an object slides down an inclined plane, is the normal force doing work? A. Yes, since the object is speeding up. B. Yes, since the normal force is perpendicular to the surface. C. No, because there cannot be motion when normal forces are present. D. No, because the normal force is perpendicular to the displacement. E. No, because the frictional forces will cause it to slow down.

D. No, because the normal force is perpendicular to the displacement.

If you double the speed of a moving object, then the kinetic energy: A. halves. B. remain the same, C. doubles. D. quadruples. E. None of the above.

D. quadruples.

A small bead slides without friction along the wire shown here, beginning at point A. The wire does not touch itself at point C, so the bead has room to slide past that point. The bead has maximum kinetic energy at point A. B. C. D. E.

E

What is the kinetic energy of a 2-kg toy car that is moving at 3 m/s? A. 0.67 J B. 1.5 J C. 3 J D. 6 J E. 9 J

E. 9 J (K.E. = (1/2)Mass X (Velocity)squared)

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

E. heat.

A small bead slides without friction along the wire (loops) shown here, beginning at point A. The wire does not touch itself at point C, so the bead has room to slide past that point. The bead has maximum speed at point A B C D E

E. speed is maximum at lowest point .

A small bead slides without friction along the wire shown here, beginning at point A. The wire does not touch itself at point C, so the bead has room to slide past that point. The bead has maximum potential energy at point A B C D E

A

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

B. momentum

A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of: A. energy. B. power. C. Both of these. D. Neither of these

B. power.

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

C. four times as much work.

An object is lifted to a given height. A second, identical object is lifted to twice the height. Compared to the first object, the second has how many times the gravitational potential energy. A. one-half B. the same C. twice D. four times E. None of the above

C. twice