College Physics (4th Edition)

$v = 100~m/s$
We can find the man's speed: $K = Q$ $\frac{1}{2}mv^2 = Q$ $v^2 = \frac{2Q}{m}$ $v = \sqrt{\frac{2Q}{m}}$ $v = \sqrt{\frac{(2)(418\times 10^3~J)}{83~kg}}$ $v = 100~m/s$