Question

The 150 N horizontal force is used to push the box 6 meters above the rough surface. If the box moves at a constant speed:

a) Work done by the force of 150 N

W = F d = (150 N) (6 m) = 900 J

b) Energy lost due to friction

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Answer 1

The box moves at a constant speed so that the resultant force acting on the box = 0.

So the horizontal force = 150 N = kinetic friction.

Energy lost due to friction:

W = Fk s = (150 N)(6 m) = 900 J