Unit 5 Review: Energy

A hiker with a backpack has a total weight of 500 N. How much work is done when she climbs 15 m in 12 sec?

• 50 J

• 60 J

• 750 J

• 7500 J

The kinetic energy of an object is shown as a function of time. What does the graph indicate about the object's motion?

• The object is accelerating.

• The object is moving at a constant speed.

• The object is decelerating.

• The object is at rest.

If the kinetic energy of an object is increasing, what can be inferred about the object's velocity?

• The velocity is decreasing.

• The velocity is constant.

• The velocity is increasing.

• The velocity is zero.

What happens to the gravitational potential energy as the object falls?

• It increases.

• It decreases.

• It remains constant.

• It becomes zero.

A second skater with mass 2M starts at the same initial height H as the original skater. Compare the second skater’s KE at the bottom of the ramp.

• KE

• 1.4 KE

• 2 KE

• 4 KE

Fill in the blank: The potential energy of an object is highest when it is at its ________.

• lowest point

• highest point

• midpoint

• moving

Fill in the blank: When friction is negligible, the total mechanical energy of a system is ________.

• increased

• decreased

• conserved

• lost

Which is the correct ranking the potential energy of carts at the top of the ramp from least to greatest? Note: Each Cart is 0.5 kg and each Block is 1.0 kg.

• A < B < C < D

• B < C < A < D

• A < D < C < B

• D < A < C < B

If a skater's mass is doubled, what happens to her potential energy at the same height?

• It doubles

• It halves

• It remains the same

• It quadruples

Fill in the blank: The potential energy of an object depends on its ________ and height.

• speed

• mass

• color

• shape