An alloy to be used for a spring application must have a modulus resilience of at least 0.79 x 106 J/m3 (0.79 x 106 Pa). What must be its minimum yield strength (in MPa)? Assume that the modulus of elasticity for this alloy is 102 GPa
Using Ur=Sig^2/2E, I am getting 401.447E6 Mpa but apparently thats wrong.