Consult Multiple-Concept Example 4 for insight into solving this problem. A copper rod is fastened securely at both ends to immovable supports. When this rod is stretched, it will rupture when a tensile stress of 2.3 × 107 N/m2 is applied at each end. The rod just fits between the supports, so initially there is no stress applied to the rod. The rod is then cooled. What is the magnitude |(T| of the change in temperature of the rod when it ruptures?