The human heart discharges `75 cm^(3)` of blood per beat against an average pressure of `10 cm` of `Hg`. Assuming that the pulse frequency is `75` per minute, the power of the heart is (density of `Hg = 13.6 gm cm^(-3)`)

Options

A. `11.9 W`
B. `1.19 W`
C. `0.119 W`
D. `119 W`

Answer

B

Explanation

`P = (dW)/(dt) = P (dV)/(dt)`
Here `p = hdg`
`= 10 xx 13.6 xx 980 = 1.3328 xx 10^(5) "dyne"//cm^(2)`.
and `(dV)/(dt) = `pulse frequency xx blood discarged per
pulse or `(dV)/(dt) = (72)/(60) xx 75 = 90 cc//sec`
`:.` Power of heart `= 1.3328 xx 10^(5) xx 90`
` = 1.19 xx 10^(7) erg = 1.19W`