Electric Ice Hockey is a video game designed to help you understand the electric forces between point charges.
When you start the game, you will see a rink, a blue "puck," a net, and a barrier. In the upper right corner you will see a pair of vaults holding positive and negative charges. When they are in the vaults, these charges have no effect, but you can use the mouse to drag them out of the vault and position them wherever you would like inside the rink. When you press the Go button, the puck will start to move in response to the net electric force applied to it. (In case you can't guess from the color, the puck is positively charged.) Your task is to guide the puck into the net.
After an unsuccessful shot, the Again button will reset the puck to it's starting position, but will leave all your placed charges where they were. If you score a goal, the Again button advances you to the next level. As with any self-respecting video game, the higher the level, the bigger the challenge.
At any level, pressing the New button gives you a slightly different version of the same level. Placed charges are moved back to the vault.
You can control the display of the net force vector with the Show Force button.
You can use the Level button to choose any level you like, including Level 0, which allows you to ask "what if " questions. The level has has no net or barriers, but a draggable puck and an "infinite" supply of charges.