In the figure provided, two suitcases are on a 7.81 m high ramp to passengers waiting in a baggage terminal. The top suitcase is released from rest, and it slides down the ramp and hits the second suitcase. If the suitcase at the top has a mass of 15.4 kg and the other suitcase has a mass of 30.8 kg, what is their combined speed if an inelastic collision is achieved? Assume the ramp to be frictionless.