We are doing Cons. of Momentum in my intro to physics class.. and I am stuck on this problem: An explosion breaks an object into two pieces, one of which has 1.58 times the mass of the other. If 7370 J were released in the explosion, how much kinetic energy did the heavier piece acquire? I'm not quite sure where to begin, it seems like the question is misisng some info.. like if the peices are travelling at the same velocity or at different velocities.. I'm guessing this is relating conservation of momentum to conservation of kinetic energy where we can get a variable to cancel out.. but i can't seem to get started.. any hints?