What is the girl's speed before and after grabbing the box on a trampoline?

[kenau_reveas]

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.

 

[civil_dude]

This involves kinematics, to find the initial velocity, and conservation of momentum to find the velocity after she grabs the box.