$($a$)$ For construction purposes a beam must withstand a bending moment of $500$ Nm $.$ If the maximum stress must not exceed $200$ kPa $,$ using calculations and the standard table for $\text{'}T\text{'}$ section Universal Beams $($provided at the end of this assessment$)$ complete the following:

Calculate the elastic modulus $\text{'}z\text{'}$ value for the beam

Select an appropriate $\text{'}$l$\text{'}$ beam suitable for this construction

Justify why you have selected this beam and not another