Question

A woman on a bridge 94.0 m high sees a raft floating at a constant speed on the river below. Trying to hit the raft, she drops a stone from rest when the raft has 5.10 m more to travel before passing under the bridge. The stone hits the water 1.20 m in front of the raft. Find the speed of the raft.

Answer 1

how long does it take to fall 94m?
4.9t^2 = 94
t = 4.38s

during that time, the raft went 5.10-1.2 = 3.9 m so its speed was
3.9m/4.38s = ____ m/s