Question

A box is pushed across the floor against a constant frictional force. The box is pushed across the room to the east in 30 seconds and returned to its starting point (pushed to the west) in 60 seconds. Which of the following is true about the work done and the power expended in both directions?

My answer: a

a. Work going east > work going west; power going east = power going west

b. Work going east < work going west; power going east = power going west

c. Work going east = work going west; power going east = power going west

d. Work going east = work going west; power going east < power going west

e. Work going east = work going west; power going east > power going west

The work going east and west is the same, since the friction force and distance moved are the same. The power is higher in the direction requiring less time.

That logic should help you pick one of the choices.

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