DC Circuits - Impedance Matching

Determine the maximum power dissipated in a load given a battery with some internal resistance.

[slazinger]

This is just what I was looking for, thank u sir for saving me a bunch of minutes of juggling with the equation.

[JayKnight]

Dang it. I came here trying to wrap my head around why there's such a thing as DC impedance... You left me hanging!

[JoeCognescenti]

Terrific, easy to understand video.  Thanks!

[mikebeim]

Excellent, thank you very much Mr. Vandrevala.
One question though: when we're expressing I-total we're using V/(r+R) for resistors in series. When expressing V-total also I*(r+R). Why then are we only using R when expressing Power (P=V-total * I-total) = I*I*R and not = I^2*(r+R).
If I is dependent on both resistors and V is dependent on both resistors, how come it's sufficient to use R and not the sum of the resistors in series?

[jacobvandijk]

I hope you will make one more video to answer the question at the end of this video ;-)

[da]

Thank you sooo much, you've helped me a lot!