A sandbag in outer space moves at 3 m/s and collides and sticks to a half-as-massive sandbag initially at rest. Compared with the kinetic energy of the moving bag before collision, the kinetic energy of the coupled bags after collision is

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Quizplus · Accepted Answer

The initial kinetic energy is (1/2)m(3^2) = 4.5m. After collision, the combined mass is 1.5m, and the velocity is 2 m/s (from conservation of momentum). The final kinetic energy is (1/2)(1.5m)(2^2) = 3m, which is two-thirds of the initial kinetic energy.

A Sandbag in Outer Space Moves at 3 M/s and Collides