Physics

Problem

0.50\,\text{kg}

ball rests on the floor of a train that moves east at

18\,\text{m/s}

relative to the ground. The ball is then thrown forward so that its speed relative to the train becomes

5.0\,\text{m/s}

. A car on a nearby road travels west (opposite the train’s motion) at

12\,\text{m/s}

relative to the ground. What is the change in the ball’s translational kinetic energy as measured by the driver in the car? a)

5.0\times10^{1}\,\text{J}

3.1\times10^{2}\,\text{J}

8.1\times10^{1}\,\text{J}

1.6\times10^{2}\,\text{J}