Free-Fall 1D Motion Problems

Name ______Free-Fall 1D Motion Problems

1) A heavy ball is dropped into a lake from a height of 30.0 m above the water. It hits the water with a certain velocity and continues to sink at this same velocity. It reaches the bottom of the lake 10.0 s after it was dropped. How deep is the lake?

2) Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are different. Suppose that the initial speed of the first arrow is 25.0 m/s and that the second arrow is fired 1.20 s after the first. Determine the initial speed of the second arrow?

3) Two stones are dropped from the edge of a 60 m cliff. The second stone is dropped 1.6 s after the first. How far below the cliff is the second stone when the separation between the two stones is 36 m and both stones are still in the air?

4) An object is dropped from a height of 120 m. Find the distance it fell during its final second in the air.

5) Another scheme to catch the roadrunner has failed. A safe falls from rest from the top of a 25.0 m high cliff towards Wile E. Coyote, who is standing at the base. Wile first notices the safe after it has fallen 15.0 m. How long does he have to get out of the way?

6) A stone is thrown vertically upward with a speed of 15.0 m/s from the edge of a cliff 85.0 m high. a) How much later does it reach the bottom of the cliff? b) What is its speed just before hitting? c) What total distance did it travel?

Answers: 1)182 m 2) 13.2 m/s 3) 11 m 4) 43.5 m 5) 0.51 s 6a) 5.97 s b) 43.5 m/s c) 108 m