Friction
The force that allows conveyor belts to work so well is, primarily, friction. Friction is defined as 'the resistance that one surface or object encounters while moving over another', or as 'the action of one surface or object rubbing against another.' The ease with which the conveyor belt moves depends on the coefficient of friction, which is 'the ratio of the force that maintains contact between an object and a surface and the frictional force that resists the motion of the object.' Basically, the coefficient of friction is the amount of force required to overcome the static friction between two objects. It is entirely dependent on the two materials at play. For example, rubber tires moving against an icy road will have a lower coefficient of friction (lower force required to begin motion) than rubber tires moving against a gravel road.
Mathematical and Scientific Concepts
Problems involving friction can, for the most part, be solved by drawing free body diagrams and employing simple equations. The most important equation involved in friction problems is shown to the left. This equation includes the coefficient of friction, net force, and frictional force. This is the equation we will be using in our experiments to calculate the coefficient of friction.