Physics (AS & A Level) · Oct / Nov 2021 · Paper 12 · Question 22

A length of metal wire is attached to a fixed point and hangs vertically. Masses are then suspended from the wire. Assume that the cross-sectional area of the wire remains constant. A stress–strain graph for the wire is plotted, as shown. What is represented by the shaded area under the graph?

1. Astrain energy in the wire
2. Bstrain energy in the wire / cross-sectional area of the wire
3. Cstrain energy in the wire / original length of the wire
4. Dstrain energy in the wire / original volume of the wire

As printed in the paper