We all have played with marbles and balls. Have you ever wondered when you roll these marbles and balls they move to some extent and stop after moving at some point time? They stop as the force called friction acts upon it.
What is friction?
Friction is defined as the resistance experienced by the surface or by an object when it is moved over the other. When two surfaces move together and the resistance offered by these surfaces is called friction. For example, when a ball is thrown it moves up till some distance and stops. The ball is acted by an external force and it stops. This external force is referred to as friction. Static friction, Sliding friction, Rolling friction, fluid friction are the four types of friction
- Frame and door sliding against each other
- Chair pulled over the floor
- Rubbing of hands together to generate heat
We observe that the surface is smooth but when the same object is viewed under a microscope, it can seem that even the smooth appearing object has rough edges due to friction. Hence we must try to reduce the friction.
Methods to reduce friction
Following are the different methods that are used for reducing the friction:
- For objects that move in fluids such as boats, planes, cars, etc, the shape of their body is streamlined in order to reduce the friction between the body of the objects as the fluid.
- By polishing the surface, as polishing makes the surface smooth and friction can be reduced.
- Using lubricants such as oil or grease can reduce the friction between the surfaces.
- When objects are rolled over the surface, the friction between the rolled object and surface can be reduced by using ball bearings.