Answer to Question #289798 in Classical Mechanics for Venu

Question

That the human heart works as a powerful and highly effective pump, as every day it receives and discharges about 7500 liters of blood, suppose that the work done (work) before is equal to the work to raise this increase of blood a height equal to its height, m ​​1.65, if you know that the density of blood is kg / m 3 1060 and acceleration m / s 9.8 Calculate the power of the heart in watts (W)

Answer 1

Let assume that each day, the human heart pumps about 7500 liters of blood.

Find mass of blood our heart pumps each day (24 hours, or 86400 seconds):

$$m=V\rho=7500·0.001·1060=7950\text{ kg}.$$

The power is

$$P=W/t=mgh/t,\\\space\\ P=7950·9.8·1.65/86400=1.49\text{ W}.$$