Question

An athlete of mass 60 kg runs for 5 minutes with a velocity of 3 m/s. What is his power?

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{Power},\mathrm{P}=\frac{\mathrm{Work}\mathrm{done}}{\mathrm{time}} \\ \mathrm{Work}\mathrm{done}=\mathrm{kinetic}\mathrm{energy}\mathrm{possessed}\mathrm{by}\mathrm{the}\mathrm{athelete},{\mathrm{E}}_{\mathrm{K}}=\frac{1}{2}{\mathrm{mv}}^2 \\ \mathrm{Mass},\mathrm{m}=60\mathrm{kg} \\ \mathrm{velocity},\mathrm{v}=3\mathrm{m}/\mathrm{s} \\ {\mathrm{E}}_{\mathrm{K}}=\frac{1}{2}\times 60\times 3^2=270\mathrm{J} \\ \mathrm{Time}\mathrm{taken},\mathrm{t}=5\mathrm{minutes}=5\times 60=300\mathrm{s} \\ \mathrm{P}=\frac{270}{300}=0.9\mathrm{W} \end{gathered}$$