what is frictional force?
The Friction force is the force exerted by a surface as an object moves across it or make an effort to move across it.There are at least two types of friction force- sliding and static friction.The friction force often opposes the motion of an object.Friction depends upon the nature of two surfaces and upon the degree to which they are pressed together.Friction plays an important role in our daily life.Without friction we are handicap.
ADVANTAGES OF FRICTIONAL FORCE
1. It becomes difficult to walk on a slippery road due to low friction. When we move on ice, it becomes difficult to walk due to low friction.
2. We cannot fix nail in the wood or wall if there is no friction. It is friction which holds the nail.
3. A horse cannot pull a cart unless friction furnishes him a rescue foot hold.
DISADVANTAGES OF FRICTION
1.It produces in various parts of machines. In this way some useful energy is wasted as heat energy.
2. Due to friction we have to exert more power in machines.
3. It opposes the motion.
4. Due to friction noise is also produced in machines.
5. Due to friction, engines of auto-mobiles consume more fuel which is a money loss.