This is probably an easy one for you. In the following circuit
simulate this circuit – Schematic created using CircuitLab
I want to calculate the active and reactive power in load R2-C3. I've calculated the voltage over these elements to be
$$u=\hat{U} \sin(\omega t + \phi) = 0.0465 \sin(1000 t + 3.53 \text{ rad}) V$$
Now I calculate the active power, P, to be
$$P = \frac{U_e^2}{R2}$$
and the reactive power, Q, to be
$$Q = \frac{U_e^2}{\Im (Z_{C3})}$$
Where $$Z_{C3}$$ is the impedance corresponding to C3 and $$U_e = \frac{\hat{U}}{\sqrt{2}}$$ is the effective value, or root mean square, of voltage u.
Am I doing this correctly?