To calculate the young modulus uncertainty do you add together the percentage uncertainty of strain and stress and if not then what do u do. Please dont send websites just tell and help me out.

Please just tell me if I AM right or wrong because the website wont do that.

I think I:
-add percentage uncertainty of stress and strain together (i think this is the total percentage uncertainty so the young modlus unceratinty??)
-then i use this percentage to find no% of those 3 values, then i write those three yound modulus plus or minus this number

is this right if npot please tell me how andwhat to do instead as that webstie cant tell me and that thing is
not what we have done in lesson yet

To calculate the uncertainty of the Young modulus, you need to consider the percentage uncertainties of strain and stress separately. The Young modulus (E) is determined by dividing the stress (σ) by the strain (ε). Here's how you can calculate the uncertainty:

1. Calculate the percentage uncertainty for strain (Δε):
- Determine the absolute uncertainty (Δ) in the strain measurement.
- Calculate the percentage uncertainty using the formula: Δε/ε * 100%.

2. Calculate the percentage uncertainty for stress (Δσ):
- Determine the absolute uncertainty (Δ) in the stress measurement.
- Calculate the percentage uncertainty using the formula: Δσ/σ * 100%.

3. Calculate the combined percentage uncertainty:
- Add the percentage uncertainty of strain (Δε) and the percentage uncertainty of stress (Δσ) together.

Note: The above method assumes that the uncertainties in strain and stress are independent and follow a normal distribution. If the uncertainties are correlated or have a different distribution, a different error propagation method might be required.

It's important to keep in mind that the uncertainty of the calculated Young modulus depends on the uncertainties in both strain and stress. Adding the percentage uncertainties together only provides an estimate of the combined uncertainty; it doesn't give an accurate representation of the actual uncertainty.

Remember to use appropriate units and consistent measurements throughout the calculations.

Honestly, you need to learn it, and not have someone tell you. You add and subtract, per this http://web.uvic.ca/~jalexndr/192UncertRules.pdf

Yes, as I understand what you are saying, you are right if your "uncertainity" is in absolute numbers. Remember, it is not possible to add 34 and .00005 .

the website is pretty clear on the division rule. Something is very wrong if you can't see that in the text presented in that short link "..that thing is not something we have done in class yet" is not an excuse for not understanding, when you have a question. I think we have to learn to learn beyond what a particular class or teacher presents. Reading does that. If you can't accept that, good luck in the future, I can't help you.