1. The problem statement, all variables and given/known data 2. Relevant equations ΣFΔt = impulse mΔv = momentum ΣFΔt = mΔv 3. The attempt at a solution I got the first part of the question (I hope I did it correctly), I just don't understand what my professor means by resultant impulse... Do I use the same equation? Is it going to be the same as a) since the boulders aren't moving?