The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times in a minute.
P=timeW.D. WD in 1 beat by heart =0.5 J WD in 72 beats by heart =0.5×72=36 J Time =1 minute =60 s ∴P=tW.D.=6036=106=0.6 W Hence, power used by heart to beat 72 times a minute is 0.6 W
