Review the problem: A Stupid Dream.

How high must Thrasher start from to be able to make it safely around the loop without falling off due to gravity?

Well, it 's a matter of gravitational potential energy and kinetic energy. Thrasher must start on his skateboard at least 12.5 ft. above the ground in order to complete the loop without falling off due to gravity.

Give me the next puzzle —
Gone to the dogs.