Flow of Charge/Voltage Difference

Today we begin our last unit: Electricity! We know that electricity is made of moving electrons, but what makes them move? It turns out all you need is a potential difference (voltage difference). When you don't have a potential difference, no charges flow and therefore there is no electricity. Watch this video of some kids touching an electric fence; until the last dude, all of those kids were at the same potential, insulated from a different potential (ground), so there was no electricity flowing through them.

Homework tonight is Electricity I - due tomorrow.