1. The problem statement, all variables and given/known data In the fig AB is a wire of diameter 0.6mm and Young modulus of the material 2x10^11Nm^-2. C is the mid point of the wire. How much will the point B go down? 2. Relevant equations Y=FL/Al where L= original length of the wire and l=extension in the wire 3. The attempt at a solution Here the entire system is in equilibrium which means that there is no net force and there is no extra acceleration caused by the system. ∑Fy=0. The distance by which the point B goes down depends on the overall extension of the wire caused by the two masses. What I tried to do is find out l1 at point C where I use L=1.5 l1= FL/AY=1.0398x10^-5m l2= 1.0398x10^-5 Total distance= l1 +l2= 2x1.0398x10^-5m= 2.0796x10^-5m. But the answer is 3.12x10^-3m. Where did I go wrong?????