If a crate slides down a 10-degree incline at constant speed, what is the coefficient of friction between the crate and the incline? What is the coefficient of friction when a crate slides down a 20-degree incline at a constant speed?

Answer 1

think about the extremes.
sin(0) = 0
sin(90) = 1
µ=0 : no friction
µ=1: total friction