Applied Mechanics and Graphic Statics
The following is not a law of static friction:

The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces
The force of friction is dependent upon the area of contact
The force of friction always acts in a direction opposite to that in which the body tends to move
The force of friction depends upon the roughness of the surface

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Applied Mechanics and Graphic Statics
The angle of friction is:

The ratio of the friction and the normal reaction
The force of friction at which the body is just about to move
The angle between the normal reaction and the resultant of normal reaction and limiting friction
The force of friction when the body is in motion

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