The lungs perform 2.4 J of work during each expansion. The number of times per minute do they expand if their power is 2 W

Work performed by lungs in every expansion w = 2.4 J

Power of lungs = 2w

Let number of expansions per minute = n

We know $P=\frac{W}{t}=\frac{Totalworkdone}{Timetaken}$

$2=\frac{n\left(2.4\right)}{60}$

$n=\frac{2\times 60}{2.4}=\frac{60}{1.2}=50$

$\therefore n=50$