1 Mark Questions for NCERT Solutions for Class 8 Science Chapter 12
Friction is the force which resists the motion of a body, while moving on a surface.
What is meant by sliding friction ?
When one surface is sliding over the other, sliding friction comes into play.
When does static friction come into play ?
Static friction comes into play to counter balance the applied force on the body.
What are lubricants ?
The substances which reduce friction are called lubricants.
What is rolling friction ?
When one body rolls over the surface of another body, the resistance to its motion is called the rolling friction.
What are fluids ?
Fluids is the common name given to gases and liquids.
Do fluids exert friction ?
Yes, fluids also exert friction.
What is meant by air resistance ?
There is friction between a moving object and the air through which it moves, known as air resistance.
What is meant by drag ?
The frictional force exerted by fluids is known as drag.
Is friction a contact force or non-contact force ?
Why is it difficult to walk on ice ?
It is difficult to walk on ice because the friction between feet and ice is less,
When a boat is moving in the river, does the water offer force of friction to its movement ?
Yes, the water opposes the movement of the boat.