Higher June 2018 Unit 2 Q18
18. Make \(c\) the subject of the following formula. [4]
\[\sqrt{gc^2 - v} = c\]| Scheme | Marks | Comments |
|---|---|---|
| For sight of \(gc^2 - v = c^2\) | B1 | |
| \(c^2(g - 1) = v\) OR \(gc^2 - c^2 = v\) OR \(-v = c^2 - gc^2\) | B1 | FT a formula with three or more terms AND with at least two terms in \(c^2\). FT until 2nd error for equivalent level of difficulty. |
| \(c^2 = \dfrac{v}{g - 1}\) OR \(\dfrac{-v}{1 - g} = c^2\) | B1 | |
| \(c = (\pm)\sqrt{\dfrac{v}{g - 1}}\) OR \((\pm)\sqrt{\dfrac{-v}{1 - g}}\) | B1 |