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प्रश्न
State two factors which directly affect the force of friction.
उत्तर
Two factors which directly affect the force of friction are:
- The smoothness of the surface.
- The presence of solid, liquid, or gas around the moving body.
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संबंधित प्रश्न
Friction depends on the ______ of surfaces.
Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?
Write true or false.
Liquids offer more friction than the gases.
Give an example to illustrate the existence of the force of friction.
Give three examples to illustrate that friction is a necessary evil.
Tick the most appropriate answer.
Friction produces
Match the following.
| Column I | Column II | |
| a) | Static friction | Viscosity |
| b) | Kinetic friction | Least friction |
| c) | Rolling friction | Objects are in motion |
| d) | Friction between the liquid layers | Objects are sliding |
| e) | Sliding friction | Objects are at rest |
We have two identical metal sheets. One of them is rubbed with sand paper and the other with ordinary paper. The one rubbed with sand paper shines more than the other. Give reason.
Friction depends on the ______ of two surfaces in contact.
Assertion: Friction always opposes the motion.
Reason: Whenever one surface moves or tries to move over another surface, the force of friction starts acting on the surfaces.
