Higher November 2018 Paper 2 Q21
21. The density of a piece of stainless steel is 7750 kg/m3, correct to the nearest 5 kg/m3.
A block of this stainless steel is in the shape of a cuboid.
The dimensions of the cuboid are 0·33 m, 0·22 m and 0·11 m, all given correct to the nearest 1 cm.
Calculate the least possible mass of the block.
Give your answer in kg, correct to 1 decimal place.
You must show all your working. [4]
| Scheme | Marks | Comments |
|---|---|---|
| Sight of least density 7747.5 (kg/m3) | B1 | |
| Sight of all least dimensions 0.325(m), 0.215(m) and 0.105(m) | B1 | Accept equivalents in cm |
| Mass \(7747.5 \times 0.325 \times 0.215 \times 0.105\) | M1 | FT provided ‘their density’ < 7748, and at least 1 of the least dimensions is correct Must be in the correct units, if cm used throughout need sight of appropriate conversion of each to m, or volume to m3 |
| 56.8(kg) | A1 | CAO, from correct working and not from premature approximation |
| (4) |