Advertisements
Advertisements
प्रश्न
Give three examples to illustrate that friction is a necessary evil.
Advertisements
उत्तर
The examples to illustrate that friction is a necessary evil are:
- If friction were absent, we would not be able to walk.
- Friction is necessary to burn a matchstick.
- It is due to friction that we can write on board by chalk.
APPEARS IN
संबंधित प्रश्न
Write true or false.
Liquids offer more friction than the gases.
Name the three kinds of friction.
Fill in the blank.
.................... is the SI unit of force.
Fill in the blank.
Smoother the surface, ................. is the frictional force offered by it.
State if the following statement is true or false. Correct the statement if it is false.
Friction helps us to grip the objects in our hand.
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.
Rolling friction is slightly greater than sliding friction.
Complete the analogy.
Knot in a thread : _____ friction : : Ball bearing : _____ 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.
