Question

A crate of mass 5 Kg is pulled directly up a rough slope, of inclination 10 degrees, by a constant force of magnitude 20N, acting at an angle of 30 degrees above the horizontal. Find the work done by the force as the crate moves a distance of 3m up the slope.

Answer 1

The 20 N force is makes an angle of 20° relative to the incline. Then the work performed by this force is

(20 N) (3 m) cos(20°) ≈ 56.4 J