Applied Mechanics - Engineering

Q1:

The angle of friction is :

A The ratio of the friction and the normal reaction

B The force of friction when the body is in motion

C The angle between the normal reaction and the resultant of normal raction and limiting friction

D The force of friction at which the body is just about to move.

ANS:C - The angle between the normal reaction and the resultant of normal raction and limiting friction

"The angle between the normal reaction and the resultant of the normal reaction and limiting friction." When a body is on the verge of moving (about to move), the friction force acting on it reaches its maximum value, which is called the limiting friction. The angle between the normal reaction (perpendicular to the surface) and the resultant of the normal reaction and limiting friction is known as the angle of friction.