Dry friction occurs when two solid surfaces are in contact under a condition of ______.

Sliding or a tendency to slide

Which type of friction acts when a body is at rest or on the verge of motion? A) Dynamic Friction B) Kinetic Friction C) Static Friction D) Fluid Friction

C) Static Friction

True or False: The coefficient of kinetic friction is generally higher than that of static friction.

False. The coefficient of kinetic friction is generally lower than that of static friction.

Riddle: I oppose the motion of sliding surfaces, yet I am not a force you can see. What am I?

Friction

The force of friction is dependent upon the types of ______ of the two bodies in contact.

Materials

In the context of tipping, the contact forces must be applied at the ______ point.

Pivot

Which of the following statements is true regarding the angle of friction? A) It is the angle made by the resultant of normal reaction and weight. B) It is constant for all surfaces. C) It is always less than 45°. D) It is defined as the angle made by the resultant of the normal reaction and frictional force to the normal reaction.

D) It is defined as the angle made by the resultant of the normal reaction and frictional force to the normal reaction.

Fill in the blank: The maximum value of frictional force when the body is at the verge of motion is called ______.

Limiting static frictional force

Short Answer: What is the primary cause of rolling resistance?

Deformation at the point of contact between a rolling wheel and its supporting surface.

When a block is just about to slide on an inclined plane, the frictional force is at its ______.

Maximum