City Guilds Model Questions Vol1 2020 Engineering Question 37

A component must have a minimum tensile strength of \(250\) MPa and a maximum density of \(2.8\) g/cm³. Two candidate materials are considered: - Material A: tensile strength \(300\) MPa, density \(3.0\) g/cm³. - Material B: a composite made by mixing 60% by volume of Material X (strength \(400\) MPa, density \(2.5\) g/cm³) with 40% by volume of Material Y (strength \(150\) MPa, density \(1.8\) g/cm³). Assuming the composite's strength and density are volume‑weighted averages, decide whether Material B satisfies both criteria. If it does, calculate the safety factor defined as \(\text{actual strength}\,/\,\text{required strength}\) and give the result to two decimal places. If it does not satisfy the criteria, answer "Reject".