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If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Write down two additional questions about earth's magnetic field that will make your presentation more informative.