Example 2: (p175-12) resistor, capacitor, and voltage source=100cos300n are all in series. If the average power dissipated by the resistor is 150W and the rms capacitor voltage is 10v, determine R and C

We assume=Im cos(t+a)i=Im cos(ot+B) The phase angle by which the voltage leads

《电路》（英文版）9-1 Instantaneous power

8-2 Superposition, source transformation and Thevenin's theorem Superposition:

We define the ratio of the phasor voltage to the phasor current as impedance

sinusoidal current or voltage at a given frequency is characterized by only two parameters an amplitude and a phase angle. The complex representation of the voltage or current is also characterized by these same two parameters

The effective value of any periodic current is equal to the value of the direct current which flowing through a resistance R, delivers the same power to r as periodic current does

In either case, leading or lagging, we say that sinusoids are out of phase () if phase angles equal they are said to be in phase(同相)

The over-damped response---- i()= A,+A, The critically-damped response-- i(t) =e (At+A2) The under-damped- response---it)e-(b1 cos+2 sino)

The complete response=the natural response+forced response