# Homework Help: Maximal power question

1. Jan 23, 2010

### nhrock3

find the R so we will have maximal power on it

so now i need to use this formula
$$P_{max}=\frac{1}{8}\frac{|\tilde{V_s}|^2}{R_s}$$
$$|\tilde{V_s}|^2=480^2+1440^2=2304000$$
R_s is the real part of the impedance (80)

$$P_{max}=\frac{1}{8}\frac{2304000}{80}=28800$$

but here it doesnt resemble at all the maximal power formula

they are counting the average power and saying something about rms
??

Last edited: Jan 23, 2010