Final answer:
The student's question involves calculating the stress, strain, and elongation for steel and aluminum rods under a tensile force. Stress is found by dividing the force by the cross-sectional area, and strain requires knowledge of each material's Young's modulus. Elongation is the product of strain and the original length of each rod.
Step-by-step explanation:
The question relates to the calculation of stress, strain, and elongation of two different materials - steel and aluminum - when subjected to a tensile force. Using the given cross-sectional areas and the applied force, we can determine the stress by dividing the force by the area.
Strain is calculated by dividing the change in length by the original length, which requires knowledge of the Young's modulus for each material. Finally, elongation is found by rearranging the definition of strain to solve for the change in length.
For the steel rod, to determine stress, we use the formula σ = F/A, where σ is stress, F is the applied force, and A is the cross-sectional area. With a force of 10,000 N and a cross-sectional area of 9.1 mm² (which is 9.1 × 10⁻⁶ m² in SI units), the stress in the steel rod is σ = 10,000 N / 9.1 × 10⁻⁶ m² = 1.1 × 10⁸ Pa.
Similarly, the strain can be found using ε = ΔL / L₀, where ε is strain, ΔL is the change in length, and L₀ is the original length. To find the elongation, which is ΔL, we use ΔL = ε × L₀ and we need the Young's modulus of the material to calculate the strain. For steel, this modulus is typically about 2.0 × 10¹¹ Pa, which allows us to compute both the strain and the elongation.