Higher November 2024 Paper 3 Q22
22 The metal used to make a sphere costs £4320
The metal costs £3.60 per gram.
Each cubic centimetre of metal has a mass of 17.3 grams.
Work out the radius, \(r\), of the sphere. [4 marks]
| Volume of a sphere \(= \dfrac{4}{3}\pi r^3\) |
| Answer | Mark | Comments |
|---|---|---|
| \(4320 \div 3.6(0)\) or 1200 or \(17.3 \times 3.6(0)\) or 62.28 | M1 | oe cost per cubic centimetre |
| their \(1200 \div 17.3\) or \(4320 \div\) their 62.28 or 69.3(6….) or 69.4 | M1dep | mass \(\div\) density total cost \(\div\) cost per cubic centimetre |
| \((r^3 =)\) their \(69.3 \times \dfrac{3}{4} \div \pi\) or [16.5, 16.6] | M1dep | oe dep on M2 |
| [2.5, 2.55] | A1 |