Advantages and Disadvantages of Friction

Previously, we learnt that friction is simply a force that tends to oppose the motion of a surface over another. These opposition can be used to an advantage or even become a disadvantage to the two surfaces in contact. Let's consider some examples of the advantages and disadvantages of friction;

Advantages of Friction

1. Friction makes it possible for us to walk and also to stop walking after getting started. The friction between our feet and the ground enables us to walk. If the ground is wet and slippery, the friction will be reduced, so we just slip and fall.

2. Friction enables the movement of automobile tyres by providing a firm grip on the roadway. The patterns of the tyres are designed to give it a firm grip on the road even in wet conditions.

3. Friction makes it possible for the locomotive to drive a train and the brakes to stop a moving car.

4. When a screw or a nail is screwed or fitted into a piece of wood, the friction between the nail/screw and the wood enables it to fit into position.

5. Friction is employed in the use of the simple grindstone to sharpen instruments such as knives and chisels.

Disadvantages of Friction

1. Due to the opposition to motion by frictional forces, machines would need to do much work (use more energy) in overcoming friction in order to move. This results in loss of energy and therefore reduces the efficiency of machines.

2. Because a lot of energy is needed to overcome friction and do much work, this energy is lost in form of heat. Therefore, friction causes the heating of engines and machines.

3. Also, moving bodies would require more effort to move against each other, this also leads to wear and tear of the moving parts.

Methods of reducing Friction

Due to the above mentioned disadvantages of friction, there is a need to reduce its effect. The three most effective ways of reducing friction are;

1. Using ball and roller bearings which acts like wheels offering rolling friction which is less than sliding friction.

2. Application of lubricants such as oil, grease, air and graphite to prevent the direct contact between the two surfaces and thus reducing the opposing force.

3. Designing the shape of a body (e.g. ships, cars etc.) to the streamlines of the fluid through which it moves, reduces the friction between the body and the fluid.