If stress is given by equation 1 which implies that stress

[jahlin]

Homework Statement

If stress is given by equation 1 which implies that stress is independent of material and the 2nd equation implies it depends on the material. Inst it a contradiction?

Homework Equations

Normal stress is given by \sigma=f/A (1)
and \sigma=E\epsilon (2)

The Attempt at a Solution

 

[Mapes]

Appearance (or lack of appearance) in the same equation doesn't imply dependence. The equation 2=xy, for example, doesn't imply that the value 2 depends on the value of x.

If strain (stress) is a known function, the associated stress (strain) is material dependent.