Disadvantages of Friction

Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

When you wear the same pair of shoes for a few months their soles wear out. This happens because of continuous friction.

Due to the friction of pencil and chalk while writing they get smaller and smaller. Similarly, continuous use of eraser while making drawings, etc., makes it smaller. While white washing the houses, etc., a painter uses sand paper. This sand paper is worn out and becomes smooth due to its repeated use on walls.

Tyres of vehicles wear out due to constant use. Because of continuous friction between tyres and roads the grooves of tyres disappear and tyres become smooth. This can cause serious accidents.

In factories where machinery is in use all the time, friction can be a nuisance. Parts of machines which rub against each other become hot and wear out quickly.

Since friction also produces heat, the engines of cars and other machinery, therefore, become very hot after running for some time.

Energy is wasted in overcoming the force of friction.

It is due to the friction between branches of trees which rub against each other, forest fires occur.

Friction reduces the speed of moving vehicles to a great extent.

Friction is a necessary evil: A matchstick lights up due to friction against the side of matchbox when we strike it. This can destroy houses when catches fire. A tyre of wheel has rough surface to have more of a friction. If there is no friction the vehicle will skid. Friction is necessary for carrying out day to day activities because without this force we cannot set the bodies in motion or stop the moving bodies. On the other hand, friction wastes energy, brings about wear and tear and slows down motion. Thus, we can say that friction is a necessary evil as without it, we cannot do our day -to-day activities and with it we lose energy, speed.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

Which of the following are correct ? (a) A matchstick lights up due to friction against the side of matchbox when we strike it. (b) Friction can destroy houses when catches fire.
A. Only (a) is correct .		B. Only (b) is correct .
C. Both (a) and (b) is correct .		D. None of these .
Right Option : C
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Question : 2

Disadvantage of friction _______________ .
A. It allows us ti hold a pen		B. It helps us to sandpaper a table
C. It wear out our shoes		D. None of these .
Right Option : C
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Question : 3

Which of the following are correct ? (a) In factories where machinery is in use only for single time, friction can be a nuisance. (b) Friction produces heat, the engines of cars and other machinery, therefore, become very hot after running for some time. (c) Energy is wasted in overcoming the force of friction .
A. Only (a) and (b) is correct .		B. Only (b) and (c) is correct .
C. Only (a) and (c) is correct .		D. All of these .
Right Option : B
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