What is friction?
Friction is an opposing
force which comes into play when one body actually moves (sides or rolls) or even tries to move over the surface of another body. Frictional force arises due to interlocking of irregular present on the two surfaces in contact. According to modern view, the frictional force arises due to strong atomic or molecular forces of attraction between two surfaces at the point of actual contact.
 |
| Friction |
Static friction
Static
friction is an opposing force which comes into play when one body tends to move over the surface of another body, but the actual
motion has yet not started. It is a self adjusting force.
 |
| Static friction |
Limiting Friction
Limiting
friction is the maximum value of static
friction. Limiting friction is maximum opposing force that comes into play when one body is just at the averge of moving other the surface of another body.
 |
| Limiting friction |
Rolling friction
Rolling
friction is an opposing force which comes into play when one body is actually rolling over the surface of another body. The value of rolling friction is much smaller than the sliding friction.
 |
| Rolling friction |
Rigid body
A rigid body is a system of particles, in which
distance between any two particles does not change under the influence of external forces.
