Final answer:
To determine the normal stress in a brass shell, one must know the force applied and the cross-sectional area of the shell. Using the stress formula σ = F / A, the stress can be calculated.
Step-by-step explanation:
The normal stress in a material like brass is calculated using the relationship between the applied force and the cross-sectional area over which the force acts. The formula for stress is σ = F / A, where σ is the stress, F is the normal force, and A is the cross-sectional area. In engineering, the Young's modulus of a material is often used in conjunction with stress and strain calculations to determine mechanical properties under load.
Considering the question, if you want to determine the normal stress in a brass shell, you would need the force applied to the shell and its cross-sectional area. For brass or any material undergoing temperature changes, thermal stress might also need to be considered if the object cannot expand or contract freely. This stress is a result of the force which is generated due to thermal expansion or contraction restrained by some means.
So, to determine the normal stress in the brass shell, the force needs to be given or calculated, and the cross-sectional area of the shell must be known. With this information, the stress can be calculated as mentioned above using the standard stress equation.