Question

Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play, ....

• A. only if the objects are solid
• B. only if one of the two objects is liquid
• C. only if one of the two objects is gaseous
• D. irrespective of whether the objects are solid, liquid or gaseous

Answer 1

The correct option is D

irrespective of whether the objects are solid, liquid or gaseous

Frictional force acts on objects irrespective of whether the objects are solid, liquid or gaseous as friction is the force between the molecules in contact with each other(adhesive force).