It looks like that is what I've already tried to do using h=Vi[B]t+1/2gt^2. I keep ending up with 2t=-15t, which doesn't work.
Your equation doesn't include t; isn't that incorrect?
Problem: An egg is thrown downwards at 2 m/s from the top of a bridge. At the same moment, a fisherman standing in a stream 30 m beneath the bridge throws a rock upwards at 15 m/s.
How fast will the stone be moving when it and the egg are at the same height above the water?
This...