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प्रश्न
Give three examples to illustrate that friction is a necessary evil.
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उत्तर
The examples to illustrate that friction is a necessary evil are:
- If friction were absent, we would not be able to walk.
- Friction is necessary to burn a matchstick.
- It is due to friction that we can write on board by chalk.
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संबंधित प्रश्न
Write true or false.
The sliding friction is more than the rolling friction.
A body needs a force F1 just to start moving on a surface, a force F2 to continue its motion and a force F3 to roll on the surface. What is
- the static friction
- sliding friction and
- rolling friction? State whether F2 is equal, less than or greater than (1) F1 and (2) F3.
Answer the following in short.
Define force. Write its SI unit.
Tick the most appropriate answer.
Force of friction comes into play when a/an
Tick the most appropriate answer.
Friction is offered by
Tick the most appropriate answer.
Friction for an object can be reduced by
Fill in the blank.
Friction is a type of .................
Answer the following in detail.
Define friction and explain how it is useful to us.
How do you feel when you touch a nail immediately after it is hammered into a wooden plank? Why?
Assertion: There is a danger of a vehicle skidding on a wet road.
Reason: The tires of the vehicle lose their grip on the road due to an increase in friction due to the presence of water on the road.
