The uniform rod BC has cross-sectional area A and is made of α mild steel that can be assumed to be elastoplastic with a modulus of elasticity E and a yield strength σY. Using the block-andspring system shown, it is desired to simulate the deflection of end C of the rod as the axial force P is gradually applied and removed, that is, the deflection of points C and C' should be the same for all values of P. Denoting by µ the coefficient of friction between the block and the horizontal surface, derive an expression for
(a) the required mass m of the block,
(b) the required constant k of the spring.
