Answer to Question #291516 in Physics for Hiter

Question

A piano of mass 350 kg moved up a rough plane which is inclined to the horizontal ground at 25° as shown in Figure 3. It is pushed by a man with force of magnitude 1700 N parallel to the plane. The coefficient of frictional force for the surface is 0.30. After the piano has moved through 3.5 m, calculate the work done by each force acting on the piano and the net work done on the piano.

Answer 1

The work done by the pushing man:

$$W_1=1700·3.5=5950\text{ J}.$$

The work done by the frictional force:

$$W_2=0.3·350·9.8\cos25°·3.5=3264\text{ J}.$$

The net work:

$$W_3=W_1-W_2=2686\text{ J}.$$