What Determines the Total Power Output of a Battery?

AI Thread Summary
The total power output of a battery is determined by the energy transformed into electric energy and the time over which it occurs. In this case, the battery supplies a current of 5.6 A for 21 seconds, converting 1410 J of chemical energy into electric energy. However, 560 J of this electric energy is lost as heat, leaving 850 J available for useful work. The confusion arises from whether to consider the total energy output as the initial 1410 J or the net 850 J after accounting for heat loss. Ultimately, total power output can be calculated using the formula P = E/t, where E can be interpreted based on the context of the problem.
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Homework Statement


A battery supplies a steady current of 5.6 A for 21 s. During this time 1410 J of chemical energy is transformed into electric energy, but 560 J of this electric energy is transformed into heat energy inside the battery. What is the total power output of the battery?


Homework Equations


P = E/t


The Attempt at a Solution


What is confusing me is: is the energy I should consider in the "total power output" the energy associated with the emf - 1410 J - or the energy associated with the terminal voltage - 1410 J – 560 J = 850 J? I don't understand why I should use one or the other.

The next question asks pretty much the same question but with emf and current, and doesn't even give a terminal voltage, so I am guessing I should use 1410 J, but I don't understand why this is. Could someone please help explain?
 
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The way I read it, the battery puts out two kinds of power, thermal, that heats its surroundings, and electrical that does what it does in the circuit. Total power would be the sum of the two.
 

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