Homework Statement
A boy at the top of a roller coaster falls through a vertical distance of 20m. What is the final speed of the boy if:
a) His initial speed was 0
b) His initial speed was 5 ms-1
Homework Equations
GPE at top = KE at bottom
mgh = 1/2mv^2
gh = 1/2v^2
v = √2gh
if...