Question

Which one of the following forces is a contact force?
(a) Force of gravity
(b) Magnetic force
(c) Force of friction
(d) Electrostatic force

Answer 1

Answer:

(c) Force of friction

Explanation:

Friction is a surface phenomenon. When two surfaces have irregularities that come in contact do they get interlocked  preventing them against sliding against each other. So, frictional force is a contact force dependent on surface.

Here, option (c) is correct. 

Gravitational force, electrostatic force and magnetic force does not depend on the surface.

Answer 2

Answer:

C is a correct answer for your question