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