A 15kg mass accelerates down a 27 degree incline at a distance of 24 m in 4.9 seconds. Determine the coefficient of friction between the mass and the incline.

Answer 1

I will set this up for you, but YOU do the calculations. Assuming it starts form rest,

d = at²/2 ⇒

a = 2d / t²

a = (mg sinθ - μmg cosθ) / m = g(sinθ - μ cosθ)

2d / t² = g(sinθ - μ cosθ) ⇒

μ = [sinθ - 2d / (gt²)] / cosθ

Note that μ does not depend on the mass. Now plug in the values below and get the final answer for μ.

θ = 27°

d = 24 meters

t = 4.9 sec

g = 9.8 m/s²

You can finish from here ( I got about 0.28).