Question

friction is applied when two surfaces in contact move relatively to each other.​

Answer 1

Question -

What is friction ?

When is it applied ?

Solution -

Friction is a force which occurs due to the resistance of motion when an object is moving over another Object .

Friction always works in the direction opposite to the direction in which the object is moving .

It is applied when two surfaces in contact move relatively to each other.

So, it is an example of force generated due to relative motion of an object with one other .

Friction generates heat.

It is a necessary evil .

It is useful in some cases and is harmful in others .

When we walk or write on the board, friction is useful .

However friction causes wear and tear to machine parts.

It hampers movement in several cases .

$\sf{ Frictional \: Force \: can \: be \: represented \: by \: - } \\ \\ F = \nu N \\ \\ \sf{ Where \: - } \\ \\ \sf{ F \: refers \: to \: Frictional \: Force } \\ \\ \sf{ \nu \: is \: the \: coefficent \: of \: Friction } \\ \\ \sf{ N \: is \: the \: Normal \: Force }$