1. The problem statement, all variables and given/known data A girl of mass m1=60 kilograms springs from a trampoline with an initial upward velocity of vi=8.0meters per second. At height h=2.0 meters above the trampoline, the girl grabs a box of mass m2=15 kilograms. What is the speed of the girl after she grabs the box? 2. Relevant equations Conservation of momentum 3. The attempt at a solution In order to find this, I have to use conservation of energy to find the velocity right before she grabs the box, then use conservation of momentum. My question is where does the momentum go as the girl is rising? Isn't momentum supposed to be conserved? I know that internal forces conserve momentum, and the only force that acts on the girl is gravity. Is gravity not an internal force?