A horizontal force of 200 N is applied to a 55-kg cart across a 15-m level surface.If the cart accelerates at 2.0 m/s²,then what is the work done by the force of friction as it acts to retard the motion of the cart?

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Quizplus · Accepted Answer

The net force on the cart is the applied force minus the frictional force. Using F = ma, the net force is 55 kg * 2.0 m/s² = 110 N. The frictional force is 200 N - 110 N = 90 N. The work done by friction is negative because it opposes the motion: Work = -frictional force * distance = -90 N * 15 m = -1350 J.

A Horizontal Force of 200 N Is Applied to a 55-Kg