Question

A body takes just twice the time as long to slide down a plane inclined at ${30}^o$ to the horizontal as if the plane were friction less. The coefficient of friction between the body and the plane is

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

$\mu =tan\theta (1-\frac{1}{n^2})=tan30(1-\frac{1}{2^2})=\frac{\sqrt{3}}{4}$