Radial/Hoop stress in a steel turbine disc

[mattyboson12]

Homework Statement

Homework Equations

-given in question

The Attempt at a Solution

I am bit confused with the boundary conditions of this problem. I understand the radial stress is zero on the inside diameter and the radial stress on the outside diameter will be the reaction to the centripetal force per m^2. So surely you need a width to calculate the radial stress on the outside diameter which isn't given in the question?

 

[KataKoniK]

Also, are we assuming the material is isotropic and homogenous? These factors will affect the final solution and should be clarified in the problem statement. Additionally, can you provide the values for the given equations or specify if they are constants or variables? This information will help me accurately solve the problem.