Young's modulus of copper by projecting a laser

[negat1ve]

Not really a problem but a concept I am having trouble understanding and I was hoping someone can explain to me better.

We performed an experiment in lab last week on finding the Young's modulus of copper by projecting a laser on the wall to magnify the effect of the change in length of the wire.

Our lab instructor told us that the precision of the experiment is NOT ruined from using a meter stick because that stress determines the order of magnitude. And that a small area means a huge stress cause of the relationship S=F/A.

Can someone please explain this to me better why the experiment is not ruined from using the meter stick. I am still a little confused. Thanks a lot!

 

[LowlyPion]

Not sure I understand exactly what you are confused about.

You might find this lecture useful however:

https://www.youtube.com/watch?v=YrRP-oGPjvk

 

[Mapes]

It unclear to me too where the "meter stick" comes into play. Can you describe the experiment and also explain why one might have thought the meter stick would cause a loss of precision?