Friction (L3)

Friction is a force that opposes ................... motion between two bodies in contact.

The shape of an aeroplane is like a

• (a) dog

• (b) bird

• (c) car

• (d) all of these

A toy car released with the same initial speed will travel farthest on

• (a) muddy surface

• (b) polished marble surface

• (c) cemented surface

• (d) brick surface

Fluids are

• (a) liquids

• (b) gases

• (c) both (a) and (b)

• (d) none of these

Four children were asked to arrange forces due to rolling, static and sliding frictions in an increasing order. Their arrangements are given below. Choose the correct arrangement.

• (a) Rolling, Static, Sliding

• (b) Static, Rolling, Sliding

• (c) Rolling, sliding, static

• (d) Sliding, Static, Rolling

You push on a tree with 20 N of force. If the tree doesn't move, the tree is pushing back on you with _____of force.

• 20N 
• 40N 
• 10N 
• 70N

There are _________ types of friction.

• 2

• 1

• 4

• 5

What is friction?

• The random force between two solids, liquids, or gases.

• The contact force between two solids, liquids, or gases that slide past one another.

• The force that creates static electricity and helps us fly.

Rolling friction is _______ than sliding and static friction

• Lesser

• Equal to

• Greater

• None of the above

Friction is indipendent of

• Nature of surface
• Normal force
• irregularities in surface
• Area of contact