Weight of rod=mg Area=A Stress= mg/A Let change of length= l' Original length=l Strain= l'/l Youngs modulus Y= (mg/A)/(l'/l) Y= mgl/Al' l'=mgl/AY
Yes answer should be 1st....bcs under own weight we use avg of top and bottom points.....
When such a question comes in which way do we have to approach