Answer
$$
8.03 \times 10^{3} \mathrm{MW}
$$
Work Step by Step
$\text { We use the formula from Problem } 43-19 \text { : } $
$$
P(t)=P_{0} k^{t / t_{\mathrm{gra}}}=(400 \mathrm{MW})(1.0003)^{(5.00 \mathrm{min})(60 \mathrm{s} / \mathrm{min}) /(0.00300 \mathrm{s})}=8.03 \times 10^{3} \mathrm{MW}
$$
