Question

A 1.0 kg block is pushed 3.0 m at a constant velocity up a vertical wall by a constant force applied at an angle of 28.0 ◦ with the horizontal, as shown in the figure. The acceleration of gravity is 9.81 m/s 2.If the coefficient of kinetic friction between the block and the wall is 0.30, find a) the work done by the force on the block.

Answer 1

The work done by the force of friction on the block:

$$W=fd\cos=(\mu F\cos\theta)d,\\ W=0.3·F\cos28°·3=0.79F.$$

Plug in F, the force that pushes the block, to get the answer.