Question

Why is the friction force considered to be a contact force?

A.) Friction affects only solid objects.

B.) Friction is produced when objects slide past one another.

C.) Friction always acts in the same direction.

D.) Friction acts in a direction opposite to the direction of an object's motion.

Answer 1

The answer should be D

Answer 2

B.) Friction is produced when objects slide past one another.

The answer is B because friction can only occur when two objects touch, or make contact.