Question

Explain how friction can be increased and decreased?

Answer 1

Friction is a force that opposes the movement between two surfaces in contact.it is present in every medium namely solids, liquids, and gases.

Friction can be increased by:

1. Making the surfaces rough.
2. Pressing the surfaces harder against each other.

Friction is desirable in many real-life situations. Thus efforts are being made to increase friction in such situations:

1. Spikes are provided in the shoes of players and athletes to increase friction and prevent slipping. The spikes are the pointed nails that get into the ground and increase friction between the shoe and the ground.
2. Gymnasts apply some course substance on their hands to increase friction for better grip.
3. Grooves are made in the soles of the shoes for better grip on the floor so that we can move safely
4. Treads are made on the tires of vehicles to increase friction.
5. Increase fluid viscosity.

Frictional force can be reduced in the following ways:

• Use of lubricants: Lubricants such as oil or grease can be used to decrease the friction between the contact surface to fill fine pores or depressions in the surface.
• Polishing: unevenness of the surface can be reduced by polishing the surface.
• By Streamlining: Fluid friction can be reduced by designing streamlined bodies like ships, boats, and airplanes.
• Use of ball bearings: In rotating machines, shafts are mounted on ball earnings.