Higher June 2018 Paper 2 Q9
9. Adanna wants to buy a ring.
The ring she wants has a mass of 12 g when made from gold.
The density of the gold in the ring is 19·32 g/cm3.
The same ring could also be made from silver.
The density of the silver in the ring would be 10·48 g/cm3.
Calculate the difference in the masses of the two rings. [4]
| Scheme | Marks | Comments |
|---|---|---|
| \(12\times10.48\div19.32\) (=6.509… g) | M2 | M1 for \(12\div19.32\ (= 0.6211\ldots)\) |
| \(12 - 6.5(\ldots.)\) | M1 | Accept 6.5(…) – 12 FT ‘their \(12\times10.48\div19.32\)’ provided < 12 |
| 5.49(06….g) or 5.5 (g) | A1 | CAO, allowing also a negative difference |
| (4) |