Final answer:
The question concerns finding the effective modulus of elasticity for a compressed bar with restrained lateral expansion. The effective modulus increases when lateral expansion is limited, influenced by the material's Young's modulus and Poisson's ratio.
Step-by-step explanation:
The question asks us to find the effective modulus of elasticity for a bar that is subject to axial compression with lateral expansion being restrained. In the presence of axial compression, the material responds according to its mechanical properties, chiefly characterized by its Young's modulus. However, when lateral expansion is restrained, an additional factor influenced by the material's Poisson's ratio comes into play.
Lateral restraint affects the apparent stiffness of the material because it involves a multiaxial state of stress, rather than simple uniaxial compression. The effective modulus of elasticity, therefore, becomes higher because the material is not allowed to expand laterally as much as it naturally would. This effect can be quantified by modifying the Young's modulus to account for the influence of the Poisson's ratio and the degree of lateral restraint.
To compute the exact value, you would need to apply the relevant equations that combine Young's modulus, Poisson's ratio, and the restraint factor. Due to the absence of this specific data and a clearly defined restraint scenario, it is not possible to give the precise numeric answer. Nevertheless, the concept of increased effective modulus of elasticity due to restrained lateral expansion remains crucial.