Hi, this is my first time posting here, looks like a good community and people get a lot of help here. Well here goes, i have this physics problem on momentum that i have never seen before and i cant get past the first step, i kind of know what i have to do. Problem 1: A boy and a dog are standing on a 110kg raft in the middle of a lake. Just as the 55kg boy dives off the raft with a horizontal velocity of 4.0m/s due EAST, the 22kg dog leaps off the raft horizontally with a velocty of 5.0m/s due north. What is the resulting velocity of the raft? for several other problems i have been using the equation Mi*Vi = Mf1*Vf1 + Mf2*Vf2 I think i have to manipulate that somehow though because im not just working on postive, negative anymore. If someone could just get me started i would greatly appreciate it.