Rod deformation with two materials in series

[Mark Nussbaum]

Homework Statement

Homework Equations

deformation=(force*length)/(elastic moduli*area)

The Attempt at a Solution

and

since most of the variable are constants it seemed like a simple plug in problem, however it seems that my use of the forces is incorrect. unfortunately we had no examples for this chapter in class and what is in the textbook has not helped me so far. the above is both equations for deformation of each rod summed together top rod first then bottom.

 

[Chestermiller]

From an overall force balance, what is the reaction force at A? What is the tension in AB? What is the tension in BC?