Question

A 20-kg boy slides down a smooth, snow-covered hill on a plastic disk. The hill is at a 10° angle to the horizontal, and the slope is 50 m long. Part A If the boy starts from rest, what is his speed at the bottom of the hill?​

Answer 1

Answer:

13 m/s

Explanation:

I assume we are ignoring friction.

The boy's PE will all be converted to KE at the bottom of the hill.

to find PE = mgh   we need to know h

   h = 50 sin 10 = 8.68 meters

     then:    PE = 20 * 9.81 * 8.68 = 1703.49 j

KE = 1/2 m v^2 = 1703 .49

            v = 13 m/s