Motion and Energy Transfer Practice Test

A cue ball (0.20 kg) moving at 3.0 m/s hits a stationary target ball (0.20 kg). After the collision, the cue ball stops and the target ball moves at about 3.0 m/s. Which object gains kinetic energy, and which loses kinetic energy?

A bowling ball ($5,\text{kg}$) rolls at $8,\text{m/s}$ toward a set of pins (total mass $2,\text{kg}$) at rest. After the hit, the ball slows to $6,\text{m/s}$ and the pins scatter with total kinetic energy about $60,\text{J}$. The ball’s kinetic energy changes from $160,\text{J}$ to $90,\text{J}$. Which statement best accounts for the energy changes?