A trolley of mass travels at

PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A trolley of mass

40\,\text{kg}

travels at

3\,\text{m/s}

. Sand is poured into it so that its mass doubles to

80\,\text{kg}

while its speed is reduced to half of the original value. Determine the new kinetic energy as a percentage of the trolley’s initial kinetic energy.