What is the formula for calculating the maximum principal stress ($\sigma_1$) in a two-dimensional stress state?
Question 2
In the context of rock mechanics, what does the term 'elastic limit' refer to?
Question 3
Which of the following best describes the significance of measuring in situ stress in mining engineering?
Question 4
If a rock sample is subjected to a normal stress of $\sigma_x = 15 \text{ MPa}$ and a normal stress of $\sigma_y = 10 \text{ MPa}$ with no shear stress, what is the maximum principal stress ($\sigma_1$)?
Question 5
What is the relationship between stress and strain in the elastic region of a material?
