A 255 kg piano slides 4.2 m down a 30° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline (Fig. 6-36). The effective coefficient of kinetic friction is 0.40 Figure 6-36
(a) Calculate the force exerted by the man. N (b) Calculate the work done by the man on the piano. J (c) Calculate the work done by the friction force. J (d) What is the work done by the force of gravity? J (e) What is the net work done on the piano? j