Higher June 2024 Paper 2 Q12
12 \(f\) is inversely proportional to \(d^2\)
\(f = 3.5\) when \(d = 8\)
(a) Find an equation for \(f\) in terms of \(d\). (2)
(b) Find the positive value of \(d\) when \(f = 10\)
Give your answer correct to 3 significant figures. (2)
Give your answer correct to 3 significant figures. (2)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(f = \dfrac{224}{d^2}\) | M1 | for \(3.5 = \dfrac{k}{8^2}\) oe \((k = 224)\) |
| A1 | for \(f = \dfrac{224}{d^2}\) oe |
Additional guidance
Accept use of \(\propto\) for the M mark
| Answer | Mark | Mark scheme |
|---|---|---|
| 4.73 | M1 | for \(10 = \dfrac{\text{``}224\text{''}}{d^2}\) or \(d^2 = \text{``}224\text{''} \div 10\) or ft their value for \(k\) provided \(f = \dfrac{k}{d^2}\) is used |
| A1 | for answer in range 4.73 to 4.733 |