Why is friction a necessary evil?
It is both good thing and bad thing for us
Why friction is necessary? (Advantages of Friction)
Or we can also say, what are the different uses of Friction
Friction is used to-
Help us walk without slipping
Friction helps in walking on the ground because friction between our soles and ground prevent us from slipping
Walking on slippery ground is difficult because friction is less there. So, we may slip
Make Moving objects Stop
If there is no friction
An object which starts moving, it will never stop
Picking and Holding Things
We would not be able to pick or hold a thing as it would slip from our hands
Helps in Writing
We are able to write because graphite particles from our pencil rub off on paper due to friction
Similarly teacher is able to write on board because chalk powder rubs off on board due to friction
If there is no friction, we would not be able to write
Lighting a matchstick
When we rub matchstick with side of matchbox,it produces heat due to friction.Without friction,we would not be able to light fire
Fixing a Nail in Wall
When we hammer a nail in wall, friction is produced between surface of nail and wall.
This friction helps in holding surface of nail properly
Why friction is evil? (Disadvantages of friction)
It wears out different products
Example
When we wear shoes,soles wear out after some time because of friction
Steps of bridges wear out because of friction
Ball bearing of machines wear out due to friction
Tyres of car wear out after some time due to friction
It increases heat which may damage machines
When we use machines for a long period,it gets heated up
This is because of friction produced
Thus friction helps in heating of machine which may damage them
Friction Slows down speed of Object
Since friction opposes motion,it slows down speed of motion
Without friction,vehicles would move faster
Friction Reduces Efficiency and Increases Costs
Because of friction,more fuel is required to run vehicles like car
Hence it increase costs of operating vehicles and reduce their efficiency
