A$($n$)61-$kg sprinter accelerates from rest to a speed of $11\mathrm{.}0$ m$/$s in $4\mathrm{.}7$ s$.$

$($a$)$ Calculate the mechanical work done by the sprinter during this time.

J

$($b$)$ Calculate the average power the sprinter must generate.

W

$($c$)$ If the sprinter converts food energy to mechanical energy with an efficiency of $25\%,$ at what average rate is he burning Calories?

Cal$/$s

$($d$)$ What happens to the other $75\%$ of the food energy being used?