1. The problem statement, all variables and given/known data A 72 kg man jumps a) If the jump results in an upward speed of 2.1 m/s, what additional upward force does the floor exert, if the person pushes the ground for 0.36 s? 2. Relevant equations F= mv/t 3. The attempt at a solution F_net = Impule/t F_byFloor - W = F_net f_byFloor = F_net + W = (mv_f / t) + mg = m ((v_f / t)+g) = 1126.32 N But, the answer in the book is 420 N, and it just ignored Weight of the person. If my Force equation (F_byFloor - W = F_net) is right? 1. The problem statement, all variables and given/known data A bee lands on one end of a floating 4.75 g Popsicle stick. After sitting at rest for a moment, it runs towards the other end with a speed of 3.80 cm/s relative to still water. The stick moves in the opposite direction at 0.12 cm/s relative to the still water. What is the mass of bee? 2. Relevant equations mv_b + Mv_popsicle = 0 3. The attempt at a solution I am confused about the velocities. Like, How the results would be changed if I use bee velocity relative to Popsicle. And, do I need to have velocities of both objects relative to some stationary thing in order to solve this problem?