Question

If the heart pushes 1 cc of blood in one second under pressure of 20000$N{m}^{-2}$, the power of heart is

• A. 0.02 W
• B. 400 W
• C. $5\times {10}^{-10}W$
• D. 0.2 W

Answer 1

The correct option is A 0.02 W

Given,

$P=20000N{m}^{-2}$

$\frac{dV}{dt}=1cc/s$

Power, $P=\frac{W}{t}=F.v=PA\frac{dx}{dt}$ (as, $F=PA$)

$P=P.\frac{dV}{dt}$

$P=20\times {10}^3\times \frac{1}{({10}^2{)}^3}$

$P=\frac{2}{100}=0.02W$

The correct option is A.