Higher November 2020 Paper 1 Q14
14 \(F\) is inversely proportional to the square of \(v\).
Given that \(F = 6.5\) when \(v = 4\)
find a formula for \(F\) in terms of \(v\).
(3)
| Scheme | Marks |
|---|---|
| \(F = \dfrac{k}{v^2}\) or \(Fv^2 = k\) oe | M1 |
| \(6.5 = \dfrac{k}{4^2}\) or \(k = 6.5 \times 4^2\) or \(k = 104\) | M1 |
Correct answer scores full marks (unless from obvious incorrect working) Answer: \(F = \dfrac{104}{v^2}\) | A1 |
| (3) | |
| (3 marks) |
Notes
M1: (NB. Not for \(F = \dfrac{1}{v^2}\))
Constant of proportionality must be a symbol such as \(k\)
M2 for \(6.5 = \dfrac{k}{4^2}\) oe
M1: For substitution of \(F\) and \(v\) into a correct formula
A1: Award 3 marks if \(F = \dfrac{k}{v^2}\) is on the answer line and the value of \(k = 104\) is found