Advertisements
Advertisements
Question
Give examples to show that friction is both a friend and a foe.
Advertisements
Solution
Examples to show that friction is a friend:
- Friction enables us to grip and catch various objects.
- It allows us to walk pleasantly on the surface.
- It helps reduce the speed of moving items.
- It will enable us to write on paper or blackboards.
- Friction prevents objects from moving from their original positions.
Examples to show that friction is a foe:
- Friction wears and tears items.
- It damages machine parts.
- Machines and tools require constant maintenance, which wastes a lot of money.
- It slows down moving objects, requiring more significant force.
- It prohibits the free movement of items.
APPEARS IN
RELATED QUESTIONS
Select the correct alternative.
Friction is reduced by
Name the two kinds of forces in nature.
State two factors which directly affect the force of friction.
Define rolling friction
Arrange the following in descending order:
- static friction
- sliding friction and
- rolling friction?
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.
What do you understand by normal force?
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.
Tick the most appropriate answer
Friction always
Tick the most appropriate answer.
Friction is offered by
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.
A moving body comes to rest due to friction alone.
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.
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.
Assertion: We can live very happily if friction is not present in nature.
Reason: The airplane shape is streamlined to reduce the effort of frictional force.
Complete the analogy.
Knot in a thread : ______ friction :: Ball bearing : ______ friction.
