Final answer:
Not enough information is provided to calculate the load required to produce the specified change in diameter for purely elastic deformation due to tensile stress on a cylindrical specimen; details such as the material's Young's modulus or ultimate tensile strength are necessary.
Step-by-step explanation:
To calculate the load required to produce a change in diameter of a cylindrical specimen when a tensile stress is applied along its long axis, the question seems to be missing some critical information such as the material of the specimen or its Young's modulus, which are necessary to relate the load to the deformation if the deformation is purely elastic. Without this information, we cannot provide a definitive answer. You would normally use the formula for longitudinal stress and strain which relates stress (σ = F/A), where F is the force and A is the cross-sectional area, with strain (ε = ΔL/L), where ΔL is the change in length and L is the original length, and the formula connects these through Young's modulus (E = σ/ε). However, without knowing E or the material's ultimate tensile strength, we cannot calculate the load required.