What are the advantages and disadvantages …

• The force which always opposes the motion of one body over another body is called frictional force or friction.

Advantages of friction:

1. We are able to walk on ground because friction between the sole of our shoes and ground prevents us from slipping over the ground.
2. Friction between tyres of a car and the road enables a car to move forward on road without skidding.
3. The brakes of a car or a bicycle work by friction.
4. We are able to write and make drawings on paper because there is friction between the tip of pencil and paper.
5. We can hold a glass tumbler in our hands because of friction between the glass tumbler and our hands.
6. We are able to fix nails in a wall due to friction.

Disadvantages of friction:

1. Friction wears away the soles of our shoes.
2. The tyres of vehicles wear out gradually due to friction.
3. Friction wears out the rubbing machine parts.
4. Friction wears out the brake pads of vehicles gradually.
5. Friction wears out steps of staircases in buildings and foot over-bridges.
6. Friction produces heat which may damage machines.