Friction depends on what factors?

State the cause of friction between two surfaces.

Frictional force always acts in the opposite direction to the direction of motion of body. Why?

Explain the types of frictions in short.

Differentiate sliding friction and rolling friction.

Explain, how can we walk so much easily on the ground.

Name three important disadvantages of friction.

name two methods of increasing friction.

write a short note on term ‘groove’.

State the reason for sprinkling of fine powders on the carrom board.

Ball bearings are sued in machinery. Explain the reason.

State the dependency of frictional force on the viscosity of fluid.

Is the friction exerted by air on moving bus?

Name the factors on which the frictional force exerted by fluid on an object moving through it depends.

Name the force which always opposes motion.

Out of static friction, sliding friction and rolling friction:

(a) Which one is the largest?

(b) Which one is the smallest?

The surface of matchbox should be rough. Explain why.

Oiling of the axis of a bicycle makes the bicycle moving easily. Comment along with the reason.

Write the use of friction.

Write the condition under which the rolling friction increases.

Give the name of material which reduces the force of friction.

Give one use of spring balance.

Why is it difficult to walk on a smooth floor?

We always apply powder to a carom board. Why?

Mention a reason which makes the steps of foot-over-bridges at railways stations to wear out slowly.

Explain why does a man slip when he steps on a banana peel thrown on the road.

Write in brief, how does a bicycle stop when its brakes are applied.

Explain why car wheels often spin on icy road.

Some machines use streamlined shape to reduce friction. Name them.

Explain the types of friction with examples.

Write a short note on term ‘drag’. Explain why objects moving in fluids should have streamlined shape.

In which ways friction between the two surfaces can be minimized?

Explain with four examples that sometimes, force of friction is desirable.

Write some disadvantages of force of friction.