posted by Priyank on .
A small parachute is dropped from a cliff. it falls at a constant speed rate 2 m/s. A small rock is dropped 20.0 seconds later. how far will the rock drop before it passes the parachute?
We want the distances fallen to be equal. The parachute falls for 20 seconds more than the rock:
2(t+20) = 4.9t^2
4.9t^2 - 2t - 40 = 0
t = 3.07
so, after about 3 seconds, the rock either passes the chute, or it hits it.