College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 7

An audio amplifier, represented by the AC source and the resistor R in Figure P21.5, delivers alternating voltages at audio frequencies to the speaker. If the source puts out an alternating voltage of 15.0 V (rms), the resistance R is 8.20 , and the speaker is equivalent to a resistance of 10.4 , what is the time-averaged power delivered to the speaker