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प्रश्न
Explain why sportsmen use shoes with spikes.
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उत्तर
Sportsmen wear shoes with spikes because they give them a better grip while running. The force of friction between the shoes and the ground increases with the help of spikes.
संबंधित प्रश्न
Friction opposes the ______ between the surfaces in contact with each other.
Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.
Fill in the blank.
We use ball bearings to .................. the friction.
Name the three kinds of friction.
The eraser gets smaller and smaller as you use it more and more. Explain the reason.
Answer the following in a word or two or in a sentence.
Which type of force acts on a string pulled from both ends?
Answer the following in a word or two or in a sentence.
Why does a rolling ball stop after moving some distance?
Tick the most appropriate answer
Friction always
Tick the most appropriate answer.
Friction produces
Answer the following in a word or two or in a sentence.
Name the force responsible for opposing the motion between two bodies in contact.
Answer the following in a word or two or in a sentence.
Name a method used to reduce friction.
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?
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 |
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.
Complete the analogy.
Knot in a thread : ______ friction :: Ball bearing : ______ friction.
