a 90.0 -kg hockey player moves at 5.0 m/s and collides head-on with a 110-kg player moving at 3.0 m/s in the opposite direction. after the collision, they move off together at 1.0 m/s . find the decrease in kinetic energy from the collision for the system containing both hockey players .

Scientists follow specific processes in order to determine valid explanations and conclusions from observations. david observed strange lights in the sky above his home outside of roswell, new mexico. the only explanation that makes sense to him is that there are ufos in the area. what should david do next to verify his explanation?