Inclined Plane Physics

Question

A 12 kg block is dragged up a hill at constant velocity. If the hill is inclined at 11 degrees and the coefficient of friction is 0.8 what force must be applied?

Answer 1

if m = mass of the block (12 kg), g = acceleration due to gravity (9.8 meters/sec²), c = angle of inclination (11 degrees), u = coefficient of friction (.8), P = pulling force uphill.

The Sum of the forces = 0 sum of forces = P -mgsin(c) - umgcos(c)

Then P = mgsin(c) + umgcos(c) = (12)(9.8)(.191) + (.8)(12)(9.8)(.9816) = 114.79 Newtons