When a man eats $100 \, g$ of ice in a minute,how much power will he get? The latent heat of ice is $80 \, cal/g$.

(560 W) Mass of ice eaten by the man per second,$m = \frac{100 \, g}{60 \, s} = \frac{5}{3} \, g/s$.
Latent heat of ice,$L = 80 \, cal/g$.
Energy required per second (Power) $P = m \times L$.
$P = \frac{5}{3} \, g/s \times 80 \, cal/g = \frac{400}{3} \, cal/s$.
Converting calories to Joules $(1 \, cal = 4.2 \, J)$:
$P = \frac{400}{3} \times 4.2 \, J/s = 400 \times 1.4 \, W = 560 \, W$.