What if hooke's law was invaild?

Question

if it were invalid,then can you use a spring to measure forces successfully? if possible, how?

Answer 1

only succesfully if it can be modelled by a function,

the thing with hookes law is that its a linear relationship, therefore you can use it for predictions and calculations etc.

Answer 2

Easily.  

The calibration marks on the scale would simply be non-linear, following whatever law you replace Hooke's with.....