A small rescue robot uses a connector in a cable system. Four replacement designs are available.
The motor can lift a connector only if its mass is no greater than 0.50 kg. Designs made from a material with a tensile strength below 350 MPa are rejected.
| Design | Material | Volume (cm3\mathrm{cm^{3}}cm3) | Density (g/cm3\mathrm{g/cm^{3}}g/cm3) | Tensile strength (MPa\mathrm{MPa}MPa) |
|---|---|---|---|---|
| A | Steel | 60 | 7.8 | 400 |
| B | Aluminium | 190 | 2.7 | 300 |
| C | Carbon-fibre composite | 330 | 1.6 | 600 |
| D | Aluminium | 150 | 2.7 | 300 |
Which design should be used?
Design B - aluminium
Design A - steel
Design D - aluminium
Design C - carbon-fibre composite
136 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.