Foundation June 2018 Paper 2 Q25
25 A force of 70 newtons acts on an area of 20 cm2
| \(\text{pressure} = \dfrac{\text{force}}{\text{area}}\) |
The force is increased by 10 newtons.
The area is increased by 10 cm2
Helen says,
“The pressure decreases by less than 20%”
Is Helen correct?
You must show how you get your answer. (3)
| Answer | Mark | Mark scheme |
|---|---|---|
| No (supported) | P1 | For a process to calculate the initial or new pressure, eg \((70 + 10) \div (20 + 10)\) (=2.6 to 2.7) or \(80 \div 30\) (=2.6 to 2.7) or \(70 \div 20\) (=3.5) |
| P1 | For a complete process to make a comparison eg. \(0.8 \times \text{``}3.5\text{''}\) (=2.8) OR \(\dfrac{(\text{``}3.5\text{''} - \text{``}2.6\text{''})}{\text{``}3.5\text{''}} \times 100\) (=22 to 26) OR \(\text{``}3.5\text{''} \times 0.2\) (=0.7) and \(80 \div 30\) (=2.6 to 2.7) OR \(\dfrac{\text{``}2.6\text{''}}{\text{``}3.5\text{''}}\ (\times\ 100)\) (=0.74 to 0.78 or 74 to 78) | |
| A1 | for a correct conclusion supported by accurate figures eg 2.8 and 2.6(6…) OR decrease is 24% (or 22% to 26%) OR 0.7 and 2.6 to 2.7 and 3.5 OR 0.7 and 0.9 OR 0.76 (or 0.74 to 0.78) OR 76% (or 74% to 78%) |
Additional guidance
Accept any value in the range 2.6 to 2.7 if unsupported by working
Allow truncation or rounding of figures