A slide-loving pig slides down a certain 35 degree slide in twice the time it would take to slide down a frictionless 35 degree slide. What is the coefficient of kinetice friction between the pig and the slide?

I know that when the coefficent of kinetic fricition is zero t=1/2 and When it is unknown t =1 but I am not sure....

Thinking. If if slides down in twice the time, its average velocity is twice, and its final velocity is twice as large. If its final veloicity is twice, the Kinetic energy is four times as much on the frictionless plane. So if the available energy is mgh, then friction is absorbing 3/4 of that energy, leaving 1/4 for KE at the bottom.

3/4 mgh= mu*m*g*cos35*distance
but distance= h/sin35
and one can solve for mu.

check my thinking. Neat question.