Advertisements
Advertisements
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.
Advertisements
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.
APPEARS IN
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?
A charged glass rod attracts a charged plastic straw.
Name the three kinds of friction.
The eraser gets smaller and smaller as you use it more and more. Explain the reason.
Give three examples to illustrate that friction is a necessary evil.
Answer the following in a word or two or in a sentence.
Why does a rolling ball stop after moving some distance?
Answer the following in short.
Define force. Write its SI unit.
Answer the following in detail.
What are the various effects of force? State one example of each.
Fill in the blank.
Weight remaining the same, friction is independent of ............. of surface in contact.
Fill in the blank.
Sliding friction and rolling friction are types of .................. friction.
Tick the most appropriate answer.
Force of friction comes into play when a/an
Tick the most appropriate answer.
A car skids on a wet or muddy road due to
Fill in the blank.
Rolling friction is ........... than sliding friction.
Fill in the blank.
Friction is a type of .................
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 detail.
Write the characteristics of the force of friction?
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.
Complete the analogy.
Knot in a thread : ______ friction :: Ball bearing : ______ friction.
