It is India vs Pakistan and Virat is batting. The ball goes straight towards the boundary and it’s a four! Now it is Australia’s batting. They have 1 ball and 4 runs to win. David Warner hits the ball hard and it is rolling straight towards the boundary. Your heart is beating fast and you cross your fingers and take the Lord’s name. You pray for a miracle. Suddenly, Ravindra Jadeja jumps from nowhere and stops the ball before it hits the boundary. India has won.
This is the magic of Friction Force! It can make you win or lose a match. Some people also say that Friction is a necessary evil. Why? Let’s dive into the advantages and disadvantages of Friction, how it helps and harms us or things around us.
But before that, What is Friction?
The Force of Friction opposes and restricts the motion of an object sliding or moving on a surface. The frictional force is always applied from the opposite direction in which the object is moving.
That was the Physics textbook definition.
Let’s look at some fun daily-life examples of the friction force as a necessary evil.
This is how friction is your friend who has got your back.
It helps you hold greasy things like glass, slime toys and oily jars.
It helps you walk on wet marble floors and tiles so that you don’t slip and hurt yourself.
You can run fast and play on muddy school grounds because of friction.
It makes writing, drawing, and colouring possible.
Friction between the chalk and the slate helps the chalk particles stick to the slate when you draw on it.
It stops the tyres of your bicycle or car and prevents accidents by applying brakes.
It also helps in moving the tyres of shopping carts in the mall.
The city of Venice is built on water using wooden friction piles.
The 400 m tall Al Hamra Tower is built on slippery desert sand in Kuwait. How? It stands on big friction piles.
Giant asteroids break into smaller ones and burn in the atmosphere before they can damage the earth. Can you guess why? Frictional Force, of course.
Remember the early men? Who discovered fire by rubbing twigs and stones? It was actually the friction caused by the stones that created sparks and caused fire.
So friction has been helping you and humankind since quite a while now.
Yet, friction can also be our enemy.
Ever got your shoes torn while racing with your friend, then tripped and fell, most probably it was friction which caused your shoe the damage. Your shoes wear out because of friction between the soles and ground.
Similarly, screws of furniture and machines become loose because of friction.
Friction causes wildfire in forests. A small spark can lead to big fires that burn trees and animals.
It causes loss of energy, like in big machines, friction heat them up while running and have to rest for some time.
The same happens with mixer jars because friction produces heat.
It wears out tyres of cars and slows down the speed and mileage. That means loss of fuel and money.
Friction causes fatal accidents. Sudden breaks cause vehicles to tumble down and overturn.
It also causes noise pollution because of the friction between moving parts of machines.
Ever done Go-Karting? The racing car is burning hot after many laps because of friction. Don’t touch it or you will burn your hand.
So, the next time you balance yourself and miss a fall on the wet floor, thank friction. And if you tumble and lose a race against your friend, blame it on friction.
Did this help you understand why friction is both good and evil? Then, you have understood your Class 8 Science Physics NCERT topic ‘Friction: A Necessary Evil’. Have a class test tomorrow? Take a free online MCQ test of Class 8 Science Chapter 12 Friction. SeekoG diagnostic tests will not only tell your score but will also suggest the topics you should practice more. Take a free diagnostic test.
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