An object is placed on the surface of a smooth inclined plane of inclination . It takes time t to reach the bottom of the inclined plane. If the same object is allowed to slide down rough inclined plane of same inclination , it takes time nt to reach the bottom where n is a number greater than 1. The coefficient of friction  is given by -

Options

A. `mu = tan theta [1- (1)/(n^2)]`
B. `mu = cot theta [ 1- (1)/( n^2)]`
C. `mu = tan theta [1- (1 )/(n^2)]^(1//2)`
D. `mu = cot theta [1- (1)/( n^2 )]^(1//2)`

Answer

A