Half Wave rectified circuit

By placing a single diode into an AC circuit we can achieve half wave rectification. This takes AC and converts it into a pulsating DC wave form. This video will go over the theory as well as the calculations involved in this circuit.

[@sliet5124]

awesome

[@stevesummers3838]

I thought power = V x I. But you say its (Vpeak x Ipeak)/2. Is this because it is AC? I'm just confused where the /2 comes from. Any help would be great. Thanks