Summary Unit 19: Gravitational and frictional forces

Forces can be of different types such as Gravitational force and frictional force.

Gravitational force is a force which pulls all objects downwards and causes objects to have weight.

While frictional force, has many effects and can be useful or even cause problems. Problems caused by frictional force are for example it can slow down objects, it could overheat engines and wear out tyres. But the problems could be overcomed using lubricants and rollers and wheels.