Answer:
Time = 13333.33 s = 222.22 min = 3.7 h
Explanation:
The total amount of energy in two cells combined will be:
[tex]Total\ Energy = 40000\ J + 40000\ J\\Total\ Energy = 80000\ J\\[/tex]
Now, we calculate the power of the batteries:
[tex]Power = (Voltage)(Current)\\Power = (3\ V)(2\ A)\\Power = 6\ Watt[/tex]
Now, we use the following formula to calculate the time the batteries will be able to deliver the power to the flashlight:
[tex]Total\ Energy = (Power)(Time)\\\\Time = \frac{Total\ Energy}{Power}\\\\Time = \frac{80000\ J}{6\ Watt}[/tex]
Time = 13333.33 s = 222.22 min = 3.7 h