Question

Mention two instances when friction between two surfaces is deliberately increased.

Justify the action in each case.​

Answer 1

Answer:

1. when the surfaces in contact are extra smooth.

2. force of friction is independent of area of the surface in contact.

Explanation:

1. when surfaces in contact are extra smooth, distance between the molecules of the surfaces in contact decreases, increasing the adhesive forces between them. therefore, the adhesive force increases, so does the frictional force.

2. this is because with the increase in area of contact, force of adhesion also increases ( in the same ratio. And the adhesive pressure responsible for friction, remains the same .