Question

what will be the power output of the heart if in each heartbeat it pumps 80 ml of blood at an average pressure of 100 mm of Mercury? (assume 60 heart beats/min)

(1) 1.07 W
(2) 1.04 W
(3) 1.035 W
(4) 1.02 W

Answer 1

The work required per beat is

W = V * (Delta P)where V is the volume pumped and delta p is the pressure increase provided.

W = 80 * 10^-6 * 100 * 1.01 * 10^5 /760

W = 1.06 Joules

Time between each neat = 60/60 = 1 sec

Hence power P = W/t = 1.06 watt