Consider two straight bars of uniform cross section made of the same material. Bar 1 has an axial length of 1m and a square cross section with side length 1mm. Bar 2 has an axial length of 3m and a round cross section with 4mm diameter.
When subjected to 1kN axial tension, bar 1 elongates by 5mm. What will be the elongation of bar 2, d2, if it is compressed axially with a load of 25kN?