Question

The heart does 1.5J of work in each heartbeat. how many times per minute does it beat if it’s power is 2W?

Answer 1

gn: work = 1.5 J

     time = 1 min = 60 sec

     power = 2 Watt

to find  : no. of heartbeats

ans:  W = Pt   = 2 X 60 s = 120 J  

V 1.5 J work is done in 1 beat.

.’. 120 J work will be done in 1.5 J= 80 beats

Therefore, number of beats per min = 80

Answer 2

Answer:

80 beats

Explanation:

: work = 1.5 J

     time = 1 min = 60 sec

     power = 2 Watt

to find  : no. of heartbeats

 W = Pt   = 2 X 60 s = 120 J  

now 1.5 J work is done in 1 beat.

therefore ,120 J work will be done in 1.5 J= 80 beats

Therefore, number of beats per min = 80