A 255 kg piano slides 4.4 m down a 30° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.40.
a. Calculate the force exerted by the man.
b. Calculate the work done by the man on the piano.
c. Calculate the work done by the friction force.
d. What is the work done by the force of gravity?© BrainMass Inc. brainmass.com October 9, 2019, 10:10 pm ad1c9bdddf
a) Fig. shows all the forces acting on the piano. Weight mg has been resolved into components mgcosθ and mgsinθ. Frictional force F and pushing force P act upwards as shown.
Frictional force F = μN = μmgcosθ = 0.4 x 255 x 9.8 x cos30O = 866 N
The expert calculates the forces exerted by the man. A step by step solution provided.