if the heart of a man pumps 4 litres of blood per minute at a pressure of 130 mm of mercury
if the density of mercury is 13.6 gcm-3 calculate the power of heart
Work done by the heart will be given by, W = P.∆V
Here, P is the pressure and ∆V is the volume of blood being pumped.
Now, pressure P = hρg
Where, h = height of mercury column = 130 mm = 0.13 m
ρ = density of mercury = 13.6 g/cm3 = 13.6 × 103 kg/m3
And, g = acceleration due to gravity = 9.8 m/s2
Also, ∆V = 4000 l = 4 × 10–3 m3
Where, t = 60 s
Using these values in the equation of power, we get P = 1.15 W
Thus, the power of heart is 1.15 watt.
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