Question

The heart of a man pumps $5$ litres 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. 1.5
• B. 1.7
• C. 2.35
• D. 3

Answer 1

The correct option is B 1.7

Given pressure $=150$

Pumping rate of heart of a man $=\frac{dv}{dt}=\frac{5\times {10}^{-3}}{60}{m}^3/s$

Power of heart $p\frac{dv}{dt}=\rho gh.\frac{dv}{dt}$

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

$=1.70N$