A piece of ice slides down a `45^(@)` incline in twice the time it takes to slide down a frictionless `45^(@)` incline . What is the coefficient of friction between the ice and the incline ? .

Answer

`0.75`

Explanation

`s=(1//2)a_(1)t_(1)^(2)=(1//2)a_(2)t_(2)^(2)`, `gsinthetat_(1)^(2)=(gsintheta-mu_(k)gcostheta)(2t_(1))^(2)`,`mu_(k)=3//4cottheta=3//4cot45=0.75`