Bending Moment - Composite Material

[CivilWork]

Homework Statement

http://www.apeg.bc.ca/reg/past-exams/documents/May2005-98-BS-6.PDF [Broken]
Page 3 - Question 2
Except that let M=60 N.m (instead of 75)

Homework Equations

Transformation Equations: Z = z * E / E(ref)

The Attempt at a Solution

Transforming the composite bar to a homogeneous one using the transformation equations, then computing the stresses.
Im getting wrong answers, what are the new z , I about neutral axis, and stresses??

 

[nvn]

Hi, CivilWork. You must show your work to get help. Read the PF rules. Also read your textbook. We aren't allowed to tell you how to approach or solve a problem. To do so would be cheating on your assignment. You must first show a valid attempt, and then someone might check your math.