Question

Each day, the human heart pumps about 7500 liters of blood. As a simple approximation, assume that the work done by the heart is equal to the work required to lift this amount of blood from a person's feet to their head. Estimate the amount of work a person's heart does in a day if that person is 1.5 m tall. (Note that the density of blood is 1050 kg/m3  and 1 liter = 0.001 m3.) Given this approximation, what is the power output of this person's heart?

Answer 1

work done in lifting a mass (m) up to a height (h) from the ground is given by - Wangh e acceleration due to gravity = 9.8 m/s² we know d = m = madre -@ density - from ① 20 W=dregn - ③ given v=7500 liter = (750x oro ullm? =. 7.5 m3 d = 1050 kg/m3 h = 1. 5m - I volume W = (1050 kg/h13) (7.5 m²) (9.8 m/s) (1.5m) W = 115762.5 J) Power = work done time I day = 24 hours = 24 X3600 s = 86400 s Power - 115 762,5 J 86400 s = 11.34 Watt