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प्रश्न
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
विकल्प
only if the objects are solid.
only if one of the two objects is liquid.
only if one of the two objects is gaseous.
irrespective of whether the objects are solid, liquid or gaseous.
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उत्तर
irrespective of whether the objects are solid, liquid or gaseous.
Explanation:
Force of friction acts in solids, liquids and gases and opposes the motion with respect to each other.
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संबंधित प्रश्न
A charged glass rod attracts a charged plastic straw.
Write true or false.
The sliding friction is more than the rolling friction.
Write true or false.
Liquids offer more friction than the gases.
Name the two kinds of forces in nature.
List three ways of reducing friction.
Give three examples to illustrate that friction is a necessary evil.
Define sliding 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.
Fill in the blank.
Rolling friction offers ............. resistance than sliding friction.
Tick the most appropriate answer.
Friction is offered by
Fill in the blank
Rolling friction is ............. than sliding friction.
Fill in the blank.
Rolling friction is ........... than sliding friction.
Fill in the blank.
Bicycles use ...................... to reduce friction between the pedals and the crank
Answer the following in short.
How can sliding friction be changed into rolling friction easily?
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?
Explain how friction can be minimized.
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.
Analogy
Objects placed at rest on earth: ______:: Bodies slide over the surface on other body: ______.
