Question

A ball rolls at a constant 100 feet per minute as it approaches a hill. It then rolls down the hill gaining speed. At the bottom of the hill, it is going at 300 feet per minute. If it took 2 minutes to roll down the hill, then what is the distance from the top of the hill to the bottom of the hill?

Answer 1

a = (Vf - Vi) / t

a = (300 ft/min - 100 ft/min) / 2 min = 100 ft / min^2

2 a s = Vf^2 - Vi^2

s = (Vf^2 - Vi)^2 / (2 * a)

s = (9 - 1) * 100^2 / 200 = 800 / 2 = 400 ft length of hill