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To recharge a 12-V battery, a battery charger must move 3.6 x 10^5 C of charge from the negative to the positive terminal. What amount of work is done by the battery charger? How many kilowatt hours is this?​

User Jiselle
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1 Answer

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Final answer:

To calculate the amount of work done by the battery charger in moving a charge from the negative to the positive terminal of a battery, you use the relationship between potential difference (voltage), charge, and work.

The work done by the battery charger to move 3.6 x 10^5 C of charge through a 12-V battery is 4.32 x 10^6 J, which is equal to 1.2 kilowatt hours.

Step-by-step explanation:

The work W done on the charge q by moving it through a potential difference V is given by W = qV. In this case, the battery has a potential difference of 12.0 V and the charger moves 3.6 x 105 C of charge.

Calculating the work done:


  • W = (3.6 x 105 C) x (12.0 V)

  • W = 4.32 x 106 J (joules)

This is the amount of work done by the battery charger in joules. To convert this to kilowatt hours, you divide by 3.6 x 106 (the number of joules in one kilowatt hour).

Converting to kilowatt hours:


  • (4.32 x 106 J) / (3.6 x 106 J/kWh) = 1.2 kWh

So the battery charger does 1.2 kilowatt hours of work to move the charge.

User Falco Alexander
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