I have pretty much figured out the problem, but i am unsure of my work. the question reads: a 330kg piano slides 3.6m down a 28degree 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. Calculate: (a) the force exerted by the man. F=mgsin(theta) =(330kg)(9.81m/s2)sin90 F= 3237.3 N Is this the correct formula to use to find the force exerted by the man?