Higher November 2019 Paper 2 Q14
14 Ralf has an iron.
He models the base as a triangle joined to a trapezium.
Not drawn accurately
(a) The iron applies a force of 25 newtons (N)
| pressure \(= \dfrac{\text{force}}{\text{area}}\) |
Work out the pressure using Ralf’s model. [4 marks]
Answer in N/cm2
(b) Is the actual pressure greater than, equal to or less than your answer to part (a)?
Tick one box.
- greater than
- equal to
- less than
Give a reason for your answer. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{1}{2}(13 + 10) \times 12\) or 138 or \(\dfrac{1}{2} \times 10 \times 8\) or 40 | M1 | oe |
| \(\dfrac{1}{2}(13 + 10) \times 12\) or 138 and \(\dfrac{1}{2} \times 10 \times 8\) or 40 or 178 | M1dep | oe |
| \(25 \div\) (their \(138 +\) their 40) | M1dep | oe |
| 0.14(0…) | A1 |
| Answer | Mark | Comments |
|---|---|---|
| less than and valid reason | B2 | eg less than and you should be dividing by a bigger number or less than and the (actual) area is bigger B1 less than |
Additional guidance
| If no box is ticked, condone if less than is clearly stated in working lines | |
| Wrong box or > 1 box ticked | B0 |
| less than and he has not included all the base | B2 |
| less than and it doesn’t cover 100% of the base | B2 |
| less than and it doesn’t include the parts outside the areas | B2 |
| less than and the area is an underestimate | B2 |
| less than and it is an underestimate | B1 |
| less than and it is only an estimate | B1 |
| less than and the answer to (a) is not the exact area | B1 |