Solutions of Friction from SCIENCE For Class 8

This introductory topic explores the concept of friction, which is the force between two surfaces that are in motion, sliding, pushing, or pulling. We learn that friction is an inseparable part of the motion.

The topic broadly divides friction into static friction and sliding friction. It also describes that a bigger force needs to be applied than the force of friction to move an object.

In this topic, we learn that frictional force changes as per the surface. The rough surface has a greater frictional force than that of the smooth surface. Activities are given for students to try and learn practically.

This topic discusses how friction is disadvantageous. Friction can lead to wastage of energy. Friction generates heat, increases the cost of motion, and even causes wearing out of the rubbing surfaces.

This topic elaborates on various measures to reduce friction. Friction is reduced on reduction of contact of surfaces by using rollers for movement, making surfaces smooth, lubrication, etc. The brake system in a vehicle is based on friction.

This topic highlights the necessity of friction in our lives. Friction is as useful as it is harmful to us. If there is no friction, we will not be able to walk properly; writing would be difficult. Several tasks we perform rely on friction.

The topic discusses methods of increasing friction where needed. In various instances, friction is mandatory, and hence, we need measures to increase friction. Few examples are provided to understand how we can increase friction.

The topic tells that air and water exert friction. The movement of boats and ships in the water is possible due to friction. Friction plays its role in the movement of an airplane in the sky.