posted by louis aaaa .
A woman on a bridge 81.6 m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 9.13 m more to travel before passing under the bridge. The stone hits the water 4.30 m in front of the raft. Find the speed of the raft.
h = 0.5g*t^2 = 81.6 m.
4.9t^2 = 81.6
t^2 = 16.65
t = 4.08 s. to hit ground.
d = 9.13-4.30 = 4.83 m. = Distance the boat traveled in 4.08 s.
Speed = d/t = 4.83/4.08 = 1.18 m/s.