A 90.0-kg hockey player moving at 5.0 m/s collides head-on with a 110-kg hockey player moving at 3.0 m/s in the opposite direction. After the collision, they move off together at 1.0 m/s. How much energy was lost in the collision?

A hungry 6.61 kg fish swimming at 2.37 m/s swallows a 0.69 kg fish that was swimming towards it at 2.72 m/s. What is the final speed (in m/s) of the formerly hungry fish?

A 2,800 kg truck jumps the median and clobbers a 940 kg station wagon in a head-on collision. You are tasked with determining the truck's initial speed for insurance purposes. An observer states that the station wagon was traveling at a speed of 25.1 m/s and that after the collision, the two vehicles stuck together and were moving at a speed of 24.4 m/s in the direction the truck was originally moving. What was the truck's original speed?

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