Drag

From DmWiki

Whenever an object travels through a fluid such as water or air, it experiences drag, a force that slows down the object so it will eventually come to a complete stop if allowed to coast free. The equation for simple drag is

where F is the drag force, v is the velocity of the object, and k is a constant that determines the strength of the drag force. The higher the value of k, the quicker objects will stop moving.

See also simple physics.