A girl of mass m_1 = 60 kilograms springs from a trampoline with an initial upward velocity of v_i = 8.0 meters per second. At height h = 2.0 meters above the trampoline, the girl grabs a box of mass m_2 = 15 kilograms. View Figure For this problem, use g = 9.8 meters per second per second for the magnitude of the acceleration due to gravity. Part A What is the speed v_before of the girl immediately before she grabs the box? Express your answer numerically in meters per second. Part B What is the speed v_after of the girl immediately after she grabs the box? Express your answer numerically in meters per second.
This involves kinematics, to find the initial velocity, and conservation of momentum to find the velocity after she grabs the box.