In one cycle, a heat engine absorbs $1\mathrm{.}72$ kJ from a hot reservoir at $277$C and expels $1\mathrm{.}24$ kJ to a cold reservoir at $27$C$.$

$($a$)$

What is the engine's thermal efficiency $($in percent$)?$

$\%$

$($b$)$

How much work is done by the engine $($in J$)$ in each cycle?

J

$($c$)$

What is the engine's power output $($in kW$)$ if each cycle lasts $0\mathrm{.}297$ s$?$

kW