Friction - Law of Motion
When two objects are in contact and one moves or has intension to move with respect to other then a force develop between the two oppose it this force is friction.
- Friction act along the surface
- Friction is an electrical force
There are two types of friction :
- Static friction : In static friction has two types
- a) Auto adjusting friction.
- b) Limiting Friction
- Kinetic Friction : In kinetic friction has two types
- Sliding Friction
- Rolling Friction
- If body is at rest and no pulling force is acting on it , force of friction is zero.
- If a force applied to move a body and it does not move , the friction develop is called static friction which is equal in magnitude and opposite in direction to the applied force ( self adjusting force)
- If a force applied to move a body and it moves the friction develop is called dynamics or kinetic friction
- When a body rolls or rotate on the surface of another body friction develop is called rolling friction
- It is due to deformation at the point of contact and depends on area of contact.
- If you are walking due to east the feet slides relatively due to west so the friction force due to east.
- Engine is connected to rear wheel of a car. When the car is accelerated, direction of frictional force on the rear wheel will be in the direction of motion.
- In cycling, the force exerted by the rear wheel on the ground make the force of friction to act in the forward direction.
- When pedaling is stopped, the frictional force in backward direction for both the wheels.