General Physics
posted by Kevin .
The 5 kg block in the figure slides down a frictionless curved ramp, starting from rest at a height of h = 3 m. The block then slides d = 12 m on a rough horizontal surface before coming to rest.What is the coefficient of friction between the block and the horizontal surface?

initial PE= work done on friction
mgh=mu*mg*sinTheta*12
solve for mu 
Theta= arc sin 3/12, or sin theta= 3/12