Question

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 :

• A. 5 W
• B. 6 W
• C. 7 W
• D. 9 W

Answer 1

The correct option is B 6 W

We know that power is the energy consumed per unit time.
$\Rightarrow$ $PowerConsumed=\frac{EnergyConsumed}{Time}$
The heart beats 72 times in one minute i.e. 60 seconds.
Energy consumed in one heart beat = 5 J
Energy consumed in 72 heart beats = 5 $\times$ 72 J
On substituting all these values, we get
$PowerConsumed=\frac{5\times 72}{60}=6W$
$\therefore$ The power consumed by the heart is $6W$.