Newton's 3rd Law Chair situation

[wooker]

Homework Statement

I would like to ask a question concerning the 3rd law. For example I want to say that I sit on a chair and it breaks. Is it logical to say that " my action force was greater than the chair's reaction force so the chair broke?" If it is not logical to say this, what would explain it? How did the chair break?

Homework Equations

F(a on b) = F(b on a)

The Attempt at a Solution

I do understand that when I sit on the chair, the chair will exert an equal force back.

 

[kjohnson]

When you sit on a chair the chair exerts a force up on you to keep gravity from accelerating you down. Likewise because of Newtons third law you apply the same force down on the chair (i.e the chair "feels" your added weight). This weight your applying down on the chair will cause some small material stress and deformation. If you apply to much weight to the chair for it to apply back up then the chair will break and you will begin to accelerate.