Answer
$Q_L=1.08\times 10^6J$
Work Step by Step
We know that:
$|W|=Pt=(200W)(10.0 min)(60\frac{s}{min})=1.20\times 10^5J$
We also know that:
$|Q_L|=K|W|$ but $K=\frac{T_L}{T_H-T_L}$
$\implies |Q_L|=\frac{T_L|W|}{T_H-T_L}$
We plug in the known values to obtain:
$Q_L=\frac{270(1.20\times 10^5)}{300-270}=1.08\times 10^6J$
