$($a$)$ How high a hill can a car coast up $($engine disengaged$)$ if friction is negligible and its initial speed is $94\mathrm{.}0k\frac{m}{h}?$

m

$($b$)$ If$,$ in actuality, a $750$ kg car with an initial speed of $94\mathrm{.}0k\frac{m}{h}$ is observed to coast up a hill to a height $16\mathrm{.}0$ m above its starting point, how much thermal energy was generated by friction?

J

$($c$)$ What is the average force of friction if the hill has a slope $2\mathrm{.}5$ above the horizontal?

$N(down$ the slope$)$