Question

Starting from rest, a body slides down a ${45}^o$ inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is

• A. 0.33
• B. 0.25
• C. 0.75
• D. 0.80

Answer 1

The correct option is C

0.75

$\mu =tan\theta (1-\frac{1}{n^2})$
$\theta ={45}^{o}andn=2\left(Given\right)$
$\therefore =tan{45}^o(1-\frac{1}{2^2})=1-\frac{1}{4}=\frac{3}{4}=0.75$