You are pushing a 53kg crate at a constant velocity up a ramp onto a truck. The ramp makes an angle of 22deg with the horizontal. If your applied force is 373N, what is then coefficient of friction between the crate and the ramp?

Answer 1

normal force = 53 * 9.8 * cos22
friction force down ramp = mu * 53 * 9.8 * cos 22
component of weight down ramp = 53 * 9.8 * sin 22
so
373 = mu * 53 * 9.8 * cos 22 + 53 * 9.8 * sin 22

Answer 2

a 15.0 kg object slides down an inclined plane that makes an angle of 30 degrees with the horizontal. The friction is 10N