Question

The heart of a man pumps $5litres$ of blood through the arteries per minute at a pressure of $150mm$ of mercury. If the density of mercury be $13.6\times {10}^{3}kg/m^3$ and $g=10m/s^2$ then the power of heart in watt is

• A. $1.50$
• B. $1.70$
• C. $2.35$
• D. $3.0$

Answer 1

The correct option is B $1.70$

Given,

$\frac{dV}{dt}=5L=\frac{5\times {10}^{-3}}{60}{m}^3/s$

Power of heat,

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

$=\rho gh\times \frac{dV}{dt}$

$=(13.6\times {10}^3)\left(10\right)\left(0.15\right)\times \frac{5\times {10}^{-3}}{60}$

$=1.70W$