Higher November 2017 Paper 2 Q7
7. The table below gives the densities, in g/cm3, of aluminium, copper, iron and zinc.
| Metal | Density g/cm3 |
|---|---|
| Aluminium | 2·70 |
| Copper | 8·96 |
| Iron | 7·87 |
| Zinc | 7·13 |
A metal sphere of radius 3·6 cm is placed on weighing scales.
The reading, in kg, shows:
1·538 kg
The sphere is made from a single metal.
Which metal is the sphere made from?
You must show all your working. [5]
| Scheme | Marks | Comments |
|---|---|---|
| Density \(\dfrac{1538}{4/3 \times \pi \times 3.6^3}\) (g/cm3) | M3 | M2 for \(\dfrac{1.538}{4/3 \times \pi \times 3.6^3}\), or with other place value error OR M1 for \(\dfrac{\text{‘digits 1538’}}{\text{‘their volume’}}\) provided ‘their volume’ is dimensionally correct OR M1 for sight of \(4/3 \times \pi \times 3.6^3\) |
| 7.86(… g/cm3) or 7.87 (g/cm3) AND states ‘iron’ | A2 | CAO A1 for 7.86(…(g/cm3)) or 7.87 (g/cm3) |
| (5) |