Question

A child and sled with a combined mass of 50.0 kg slide down a frictionless hill that is 7.34 m high. If the sled starts from rest, what is the mechanical energy of the system, and what is the sled’s speed at the bottom of the hill?

Answer 1

m g h = 50 * 9.81 * 7.34 = 3600 Joules
Ke at bottom = (1/2) m v^2 = 3600 Joules
50 v^2 = 7200
v^2 = 144
v = 12 m/s