Higher November 2021 Paper 6 Q8
8
(a) Train A travels 120 km at a constant speed of 80 km/h.
Train B travels 120 km at a constant speed of 50 km/h.
Train B travels 120 km at a constant speed of 50 km/h.
How many more minutes does train B take to travel 120 km than train A? [4]
(b) Train C has a speed of \(x\) km/h.
Write an algebraic expression for train C’s speed in metres per second. [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 54 nfww | 4 | B3 for 90 [min] and 144 [min] or for 0.9 [h] or B2 for 90 [min] or 144 [min] or for A: 1.5 [h] and B: 2.4 [h] or M1 for evidence of time = distance ÷ speed | For B3 and B2 accept 1 h 30 min and 2 h 24 min |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(\dfrac{1000x}{3600}\) oe isw | 2 | B1 for \(1000x\) [m/h] or \(\dfrac{x}{3600}\) [km/s] or \(\dfrac{x}{1000 \times 3600}\) oe | For 2 marks the final answer must not have any units within the expression isw wrong simplification after correct answer Accept \(\dfrac{x}{3.6}\) and (0.277 to 0.28)\(x\) For B1 allow \(x \times 1000\) or \(x \div 3600\) or these clearly implied in a longer calculation |