by Question 1. (25 %) Write the formula for the thermal expansion of an element and explain all the variables in the formula.
Question 2. (25%) Explain Poisson’s ratio (sketch a graph and write formula)?
Question 3. (50%) Compute the polar moment of inertia for the ring cross-section shown in the figure below. Define the double integral, solve it (step by step), and express the results in terms of 
and 
