The angle between the resultant contact force and the normal force exerted by a body on another is called the angle of friction. If is the angle of friction and is the coefficient of static friction, which of the following relationships is valid?

Step-by-step solution

Let N be the normal force and f be the force of friction between the two bodies. The resultant contact force makes an angle with the normal force. From the geometry of the forces, we have: = f N For static friction, the frictional force satisfies the inequality f N , where is the coefficient of static friction. Substituting this into the equation for , we get: N N Taking the inverse tangent on both sides, we obtain: ⁻¹