Science
posted by Christina on .
A stationary roller coaster at the top of its path is 30m about the ground. The car and its passengers have a mass of 400kg. What is the velocity of the car when it reaches the ground lever? The formula for velocity is (Distance/time)

the gain in Kinetic energy is equal to the loss of potential energy
1/2 m v^2=mgh
solve for v 
mass cancels out, irrelevant
m g h = (1/2) m v^2
2 g h = v^2
v = sqrt (2 g h)
v = sqrt (2*9.8*30)
v = 24.2 m/s