The above square hollow bar is subjected to an axial force P. The bar is made of a metal alloy having the showing stress-strain diagram. [10 Pts] the modulus of

elasticity, E, b. [10 Pts] the axial stiffness, K, c. [10 Pts] the modulus of resilience, ur, and c. [10 Pts] the modulus of resilience, ur, and