Hey just stuck on this question thanks!

This amusement park has a water park section. Inside is a waterslide that travels down on an incline at an angle of 60.0 degrees above the horizontal, and stands 50.0 m tall in the air. The frictional co-efficient between wet fiberglass and the raft is 0.25. How fast will the rider be going at the bottom of the slide? Must solve using forces, NOT energy.