An 80kg person is cruising along on a 2kg longboard at 3m/s when they jump off the longboard. Right after the person jumps off the longboard their velocity is 2.8m/s in the same direction they were initially traveling. A. What is the initial momentum of the person? B. What is the initial momentum of the longboard? C. What is the final momentum of the person? D. What is the final momentum of the longboard? E. What is the final velocity of the longboard? F. What is the initial total kinetic energy of the system? G. What is the final total kinetic energy of the system? H. Comment on your answers to F. and G. and why they might be the same/different