1. The question is, What is the largest angle from the up-right position can a chair lean with mass m with out sliding out and falling? The coefficient of static friction is Mu s. In other words, at what angle with the static friction become kinetic friction.

2. Originally Posted by phys91
The question is, What is the largest angle from the up-right position can a chair lean with mass m with out sliding out and falling? The coefficient of static friction is Mu s. In other words, at what angle with the static friction become kinetic friction.
Just leaning my pen over to the point where it slides along my desk, there is an angle, but there are lesser angles from the vertical where the pen slides if there is an additional downward force. So I'm tending to think that the mass on the chair will have a bearing on it too.

3. The coefficient of static friction is equal to the tangent of the maximum angle of an inclined plane at which the object starts to slide.
The coefficient of kinetic friction is equal to the tangent of the angle of an inclined plane when the object is sliding at constant velocity.

Those angles are the arctans of coefficients.

The coefficient of static friction is greater than of kinetic friction. The angle is of couse greater also..

4. by gollie that was interesting.
"Physics: Inclined Planes: Proving Coefficient of Friction = Tan Theta"
Physics: Inclined Planes: Proving Coefficient of Friction = Tan Theta - YouTube