Friction is the force that opposes the motion of an object when the object is in contact with another object or surface. Friction results from two surfaces rubbing against each other, it can slow the motion of an object or completely prevent an object from moving at all. Without friction, my favorite sport, Supercross, would be impossible. Supercross is indoor dirtbike racing, over a course that is riddled with jumps, whoops and sharp, almost 360 degree, turns.
             Friction helps people convert one form of motion into another. For example, when people walk, friction allows them to convert a push backward along the ground into forward motion. Similarly, when Jeremy McGrath's1 dirtbike tires push backward along the ground, friction with the ground makes the tires roll forward to a stunning victory over his competitors. Friction also causes the painful injuries that Seth Enslow 2 faces when he crashes his bike off of a two hundred and fifty-foot sand dune and slides to a stop.
             Sliding friction occurs when a wheel, ball, or cylinder rolls freely over a surface, this is the friction that keeps Supercross races packed with action, and moving bikes. Static friction, in contrast, acts between surfaces at rest. Static friction is the friction that riders must overcome at the start of each race to win the Holeshot Award3.
             Friction, it seems, has good and bad parts about it. Good when it is keeping the bikes up right and moving but bad when someone falls and slides along the dirt. As much as my favorite riders may hate friction when they hit the dirt or pavement that they are riding on, without friction they wouldn't be able to ride at all. I think that the Supercross riders may be able to improve their standings if they all took a good look at the effects of friction!
             1. Seven time 250cc EA Sports Supercross Champion, the undisputed King of Supercross
             2. Madman on a motorcycle, star of 4 Crust Demons of Dirt videos...