Advertisements
Advertisements
प्रश्न
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
पर्याय
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.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Friction depends on the ______ of surfaces.
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.
When you apply brakes, the bicycle stops and the rim of the wheel becomes hot? Explain the reason.
Fill in the blank.
.................... is the SI unit of force.
State if the following statement is true or false. Correct the statement if it is false.
If two forces acting in opposite directions on a body arc of equal magnitude, then the body will not move.
Answer the following in short.
Define force. Write its SI unit.
Fill in the blank.
More the roughness of a surface, greater is the ........................
Fill in the blank.
Rolling friction offers ............. resistance than sliding friction.
Fill in the blank.
The force of friction acting between two bodies in contact while at rest is known as ................ friction.
Fill in the blank.
Sliding friction and rolling friction are types of .................. 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
State if the following statement is true or false. Correct the statement if it is false.
Friction is offered by all the three states of matter.
A moving body comes to rest due to friction alone.
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 |
Is there any possibility of making a special device to measure the magnitude of friction directly?
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: 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.
