In Fig. 2.32a, let the tensile and compressive residual stresses both be 10,000 psi and the modulus

Question:

In Fig. 2.32a, let the tensile and compressive residual stresses both be 10,000 psi and the modulus of elasticity of the material be 30 × 106 psi, with a modulus of resilience of 30 in.-lb/in.3. If the original length in diagram
(a) Is 20 in., what should be the stretched length in diagram?
(b) So that, when unloaded, the strip will be free of residual stresses?