Question

zybooks One AA battery in a flashlight stores 9400 J. The three LED flashlight bulbs consume 0.5 W. How many hours will the flashlight last?

Answer 1

Answer:

The time for which the flashlight last is 5.23 hours.

Explanation:

Given that,

One AA battery in a flashlight stores 9400 J, E = 9400 J

Power consumed by the LED flashlight bulbs, P = 0.5 W

We need to find the time for which the flashlight last. The power of a device is given by the energy stored per unit time as :

$P=\dfrac{E}{t}$

$t=\dfrac{E}{P}$

$t=\dfrac{9400\ J}{0.5\ W}$

t = 18800  seconds

or

Since, 1 hour = 3600 seconds

t = 5.23 hours

So, the time for which the flashlight last is 5.23 hours. Hence, this is the required solution.