Physics

Problem

A trolley of mass

12\,\text{kg}

is moving with a speed of

2\,\text{m/s}

. After unloading some boxes, its mass becomes

6\,\text{kg}

and its speed rises to

6\,\text{m/s}

. What is its kinetic energy after the unloading? a)

54\,\text{J}

216\,\text{J}

108\,\text{J}

96\,\text{J}