Arrange in correct increasing order the various frictional forces :

• rolling friction, static friction, dynamic friction, fluid friction

• static friction, dynamic friction, fluid friction, rolling friction

• fluid friction, dynamic friction, rolling friction, static friction

• fluid friction, static friction, rolling friction, dynamic friction.

You spill a bucket of soapy water on a marble floor accidently. Would it make easier or more difficult for you to walk on the floor? Why?

Explain why sportsmen use shoes with spikes.

Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

Explain why sliding friction is less than static friction.

Give examples to show that friction is both a friend and a foe.

Explain why objects moving in fluids must have special shapes.

What is force of friction?

What is the cause of friction between two surfaces?

Which is small sliding friction or static friction?

Which force helps to write by chalk on black board?