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प्रश्न
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.
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उत्तर
While rubbing with sandpaper, more frictional force is produced between the layers of metal sheet and sandpaper which causes more force on dust particles and they are removed easily, so it will shine more.
But in case of ordinary paper, the force of friction is not sufficient to remove all the dust, so it will shine less in this case.
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संबंधित प्रश्न
Name the three kinds of friction.
Define static 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
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Answer the following in short.
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Friction for an object can be reduced by
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Friction produces
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If you pour some oil onto a floor, the friction would
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Name the force responsible for opposing the motion between two bodies in contact.
Answer the following in short.
When you push something heavy, the resistance you feel decreases as soon as the object starts moving. Explain the reason.
Answer the following in short.
Define rolling friction and give an example where rolling. friction comes into play.
Answer the following in short.
List the various states of matter that offer frictional force?
Complete the analogy.
Knot in a thread : _____ friction : : Ball bearing : _____ friction
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Friction depends on the ______ of two surfaces in contact.
Analogy
Objects placed at rest on earth: ______:: Bodies slide over the surface on other body: ______.
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.
