Q.30 The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by the heart if it beats 72 times in a minute.

Hint: Power = Tota work done  Total time .
Step 1: Find total work done by heart in 60 minutes.

Given, average work done by a human heart per beat = 05 J

Total work done during 72 beats

             =72×0.5J=36JStep 2: Find power used by the heart Power = Work done  Time =36J60s=0.6W