Question

State True or False

Each time the heart beats, it requires 5 J of energy. If it beats 72 times in one minute then the power consumed by the heart is 360 W.

• A. 2W
• B. 4W

Answer 1

The correct option is B

4W

Power is defined as the work done per unit time.
The heart beats 72 times in one minute. So, in one second it will beat $\frac{72}{60}$ times and as in one beat it consumes an energy of 5J, in $\frac{72}{60}$ times it will consume $\frac{72}{60}\times 5=6J$
$6J$ , which is also the energy consumed in one second.
Hence, Power $=6W$