posted by Aulivia .
A 30-kg child coast down a hill on a 20-kg sled. She pushes off from the top of the hill with a velocity of 1 m/s. At the bottom of the hill, she is moving 4 m/s. If there is no heat generated when she slides down, how high is this hill?
finalKineticEnergy=InitialKE + PE
1/2 m 4^2 = 1/2 m (1)^2 + mgh
solve for height h.