I'm quite confused about impact force and weight, as well as momentum. Assuming someone were to fall from a 5-story building, about 20 m, how would you calculate the force upon impact? I know it involves momentum, but I can't quite grasp it. Also, if someone fell from the building, but instead of landing on the concrete below, they instead landed on a trampoline or blanket suspended above the ground, something that would slow them down without being lethal, how would you show that? Would it involve the same equation? EDIT: I'm ignoring air resistance as well. In case that changes things.