1. The problem statement, all variables and given/known data A 35-kg child goes down a hill on a 5-kg sled. Starting from rest, she reaches a speed of 30 km/h at the bottom of the hill. The hill makes an angle of 25 degrees with the horizontal. (a) Assuming there is no heat generated by friction and air resistance, how high is the hill? I don't really know how to solve this problem, help, please?