Question

a roller coaster can travel a maximum speed of 31.0m/s at ground level. Determine the minimum speed the coaster would be travelling at if the highest point of the track is 45.0m off the ground.

Answer 1

$\frac{mv^2}2=mgh+\frac{mu^2}2,$

$u=\sqrt{v^2-2gh}=8.8~\frac ms.$