An insect crawls up a hemisherical surface very slowly .The coefficient of friction between the insert and the surface is `1//3` If the line joining the center of the hemisherical surface of the insert makes on angle a with the verticle , find the maximum possible value of a

Options

A. `cot alpha = 3`
B. `sec alpha = 3`
C. cosec `alpha = 3`
D. None

Answer

a

Explanation

`mg sin alpha = mu mg cos alpha, cot alpha = 1//mu = 3`