posted by Lesley .
A children’s roller coaster is released from the top of a track. If its maximum speed at ground level is 8 m/s, find the height it was released from.
(1/2)MVmax^2 = M g H
Cancel out the M's and solve for H.
(This neglects friction and extra rotational kinetic energy of the wheels. It will give you an approximate answer that is an upper bound)