Question

A small body B starts from rest at the highest point A of a large fixed sphere, with centre C, and slides down with a small but constant speed. Then, the coefficient of friction between B and the sphere, at any point P on the surface of the sphere such that ∠ACP = θ, must be equal to 

(a) sinθ 

(b) cosθ 

(c) tanθ 

(d) |cosθ - sinθ|

Answer 1

Correct Answer is: (c) tanθ 

mgcosθ = N

mgsinθ = F = μN = μ mgcosθ

or μ = tanθ.