The extension of a copper wire is recorded for several different forces acting on the wire. A graph is drawn to illustrate how the force on the wire changes with extension. The greatest force is applied at point P. Which statement must be true?
- APoint R is the limit of proportionality.
- BThe elastic potential energy of the wire at point S is given by the area under the graph between points T and S.
- CThere is no plastic deformation between points Q and P.
- DThe wire obeys Hooke’s law up to a point between R and Q.