Alida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be

To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?

Fine powder is poured on the carromboard to

A boy rolls a rubber ball on a wooden surface. The ball travels a short distance before coming to rest. To make the same, ball travel longer distance before coming to rest, he may

The fishes swim easily in the water because they have

Friction produces _________ 

________ is produced by friction.

We pour a drop of oil on the hinge of door to __________ friction.

Cars and speedboats are _______ to reduce drag.

The soles of our shoes get worn out after a period of time. It is due to ___________

Name the force that always opposes the applied force.

Name the friction when wheels are used to carry heavy weights.

Name the friction that is overcome by most machines by the use of ball bearings. Name the type of friction with which it is replaced.

What makes it difficult to walk on wet floor?

Can we reduce friction to zero?

Name the force helps to writs ty chalk on blackboard.

Explain fluid friction in brief.

Liquids and gases are called as fluid. Why?

What do you mean by lubricants?

Name two methods of reducing friction with examples.

Explain why sliding friction is less than the static friction.

Is there a force of friction between the wheels of a moving train and iron rails? If yes, name the type of friction. If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?

Two boys are riding their bicycles on the same concrete road. One has new tyres on his bicycle while the other has tyres that are old and used. Which of them is more likely to slip while moving through a patch of the road which has lubricating oil spilled over it?

What is the cause of friction?

Why is it easy to drag a mat when nobody is sitting on it but difficult when somebody is sitting on it?

Explain some examples where we have to reduce the friction.

Discuss the various ways to reduce the friction.