Answer to Question #91263 in Mechanics | Relativity for Umar

Question

A body of mass 6N rest on a plane inclined at 30 degree to horizontal.
a) what force keeps it from sliding down on the plane?
b) what is the coefficient of the friction?

Answer 1

1) Holds the force of friction.

2)

$F = \mu N$ $\mu = F/N$ $\mu = {mg\sin\alpha \over N} = {mg\sin\alpha \over mg\cos\alpha } = \tan \alpha$

$\mu = \tan 30^o$

$\mu = \sqrt{3} / 3 = 0.577$

Answer: 1) friction force; 2) 0.577