The heart of a man pumps 5 liters of blood through the arteries per minutes at a pressure of 150 mm of mercury. If the density of mercury by `13.6 xx 10^(3) kg//m^3` and `g = 10 m//s^2` then the power of heart in watt is

Options

A. `3.0`
B. `1.50`
C. `1.70`
D. `2.35`

Answer

C

Explanation

Here, volume of blood pumped by man.s heart,
V = 5 litres = `5 xx 10^(-3) m^(3) ( :. "1 litre " = 10^(-3) m^(3))`
Time in which this volume of blood pumps,
`t = 1 "min" = 60 s`
Pressure at which the blood pumps
`P = 150 mm " of Hg" = 0.15 m of Hg`
`= (0.15 m) (13.6 xx 10^(3) kg//m^3) (10 m//s^2) " " ( :. P = h rho g)`
`:.` Power of the heart = `(PV)/t`
`= ((20.4 xx 10^3 N//m^2)(5 xx 10^(-3) m^3))/(60s) = 1.70 W`.