A 30 m long aluminum bar having a diameter of 50 mm is subjected to a tensile stress of 172 MPa. Find the final diameter of the aluminum bar if E=69116MPa and Poisson's ratio=0.4?
I saw you posted your question in the "Problem of the Week" forum, but I am sorry, that forum is meant ONLY for directors to post a problem on weekly basic. Do you mean to provide a challenge problem for our members to attempt at a solution, or do you mean to ask for help there?
As a temporary measure, I have moved your thread to other forum, assuming you wanted to get some help to answer the problem. :)