During braking

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

During braking, a

1200\,\text{kg}

car slows uniformly from

25\,\text{m\,s}^{-1}

15\,\text{m\,s}^{-1}

4\,\text{s}

. What is the magnitude of the average power dissipated by the brakes? (a)

90\,\text{kW}

(b)

30\,\text{kW}

(c)

60\,\text{kW}

(d)

120\,\text{kW}