Question

The power of a heart which pumps 5*10^3 cc of blood per minute at a pressure of 120 mm

Answer 1

Hi.mate

WORK DONE W IS GIVEN BY

W = F X D

F = PA (PRESSURE X AREA)

OR W = P A.D = P (AD) = P V

OR WORK DONE = PRESSURE X VOLUME

HERE PRESSURE P = 130mm OF Hg = 105 * 130/760

OR P = 13 x 105 / 76 Pa

VOLUME V = 4L = 4000 cm3 = 4x10-3 m3

HENCE W = PV = (13 x 105 / 76 ) x 4x10-3

OR Wok done = 68.42 JOULES

NOW THE PUMPING OF 4 L OF BLOOD IS DONE IN 1min = 60s

THUS POWER = WORK DONE/TIME

OR POWER = 68.42/60 = 1.1403 WATTS