Dream

Mechanical Lab , Mini Project

Friction

Presented to Dr. Tariq Saeed Khan

Reg. No . 2009166

Friction

Force diagram for block on ground. Arrows are vectors indicating directions and magnitudes of forces. W is the force of weight, N is the normal force, F is an applied force, and Ff is the force of kinetic friction which is equal to the coefficient of kinetic friction times the normal force. Since the magnitude of the applied force is greater than the magnitude of the force of kinetic friction opposing it, the block is accelerating to the left.
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. It may be thought of as the opposite of "slipperiness".
There are several types of friction:
* Dry friction resists relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into static friction between non-moving surfaces, and kinetic friction between moving surfaces.
* Fluid friction describes the friction between layers within a viscous fluid that are moving relative to each other
* Lubricated friction is a case of fluid friction where a fluid separates two solid surfaces. Skin friction is a component of drag, the force resisting the motion of a solid body through a fluid.
* Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation. When surfaces in contact move relative to each other, the friction between the two surfaces converts kinetic energy into heat. This property can have dramatic consequences, as illustrated by the use of friction between pieces of wood to start a fire.
Another important consequence of many types of friction can be wear, which may lead to performance degradation and/or damage to components. Friction is a component of the...