Friction
- Surface irregularities catch onto one another, causing surfaces to resist motion.
- There is friction between a stationary object on an inclined surface because friction stops block from sliding down.
- There is less frictional force between the shoes of the person and a wet floor compared to the friction between the shoes and a dry floor. Since there is less fiction, a person may fall down more easily.
- When his hands are sweaty, the sweat from his hands acts as a lubricant reducing the friction between the fingers and the bowling ball. This will cause him to have a loose grip and poor control of the ball.
- The powder helps to absorb the sweat from the hands, thus giving the rock climber a better grip on the rope. It also increases the friction between the climber’s hands and the rope, giving him a better grip and a lesser chance of falling off.
- Fire is started using the fire pole method. A groove is cut on the soft wood, and then a stick made of hard wood is rubbed in the groove until a fire starts. There is friction between the hard wood and the groove, generating heat which causes sparks. The soft wood catches fire.
- The earthworm has moist skin so that it lubricates itself and moves through soil easily. Its moist skin helps reduce friction between the earthworm and the soil, thus helping it move smoothly.
- When she rubs her wet hands together, frictional force will be produced and there will be heat energy, causing the water droplets to gain heat from her hands and evaporate at a faster rate, making her hands dry more quickly.
- The ball bearings reduce friction between the spinning toy and the air, allowing less air resistance faced by the toy and helping it spin for a longer time.
- Ball bearings are also used to reduce friction between moving parts of machines, cars and in-line skates. Placed between moving parts, they roll around and prevent moving parts from rubbing against each other. This reduces the wear and tear to these parts.
- In carrom, when talcum powder is poured on the board, the striker disc can travel a longer distance. This is because the tiny beads of powder act as tiny rollers that reduce friction between the striker disc and the board.
- Polishing a surface removed surface irregularities.
- On a rainy day, a moving vehicle may skid on wet roads. Its tyres need to have more grip on the road to prevent skidding. So tyres are designed with treads - grooves that quickly channel water out from underneath the tyres. This improves the grip of the tyres on wet roads, thus preventing skidding.
- Air resistance is a type of friction in air. To achieve a safe landing, a skydiver increases air resistance significantly by making use of the much larger surface area of an open parachute.
- Living things that move in air and water overcome friction by having streamlined body shapes.