A 100 kg roller coaster car is located at the top of a hill where the height is 20 m. What is the velocity when it reaches the bottom of the hill?

Answer: the final velocity is 19.8 m/s

The velocity of the car at the bottom of the hill=19.8 m/s

mass = 100 kg

height = h=20 m

Velocity at the bottom=V

Using the law of conservation of energy

potential energy at top = kinetic energy at the bottom

m g h = 1/2 m v²

g h = 1/2 v²

9.8 (20) = 1/2 V²

V=19.8 m/s

Thus the velocity of car at the bottom of hill=19.8 m/s