A runner of mass reaches the top of a staircase high in and is still moving with a…

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

Problem

A runner of mass

70\,\text{kg}

reaches the top of a staircase

5\,\text{m}

high in

4\,\text{s}

and is still moving with a speed of

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

at the top. Take

g = 10\,\text{m\,s}^{-2}

. Determine the average power developed by the runner. (a)

945\,\text{W}

(b)

875\,\text{W}

(c)

910\,\text{W}

(d)

1.40\times10^{3}\,\text{W}