| Exam Board | Edexcel |
|---|---|
| Module | AS Paper 2 (AS Paper 2) |
| Session | Specimen |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Constant acceleration (SUVAT) |
| Type | Find acceleration from distances/times |
| Difficulty | Standard +0.3 This is a standard two-part SUVAT problem requiring students to set up simultaneous equations from given distances and times. While it involves algebraic manipulation with two unknowns (initial velocity and acceleration), the approach is routine and well-practiced in AS mechanics courses. Slightly above average difficulty due to the algebraic setup, but still a textbook-style question. |
| Spec | 3.02d Constant acceleration: SUVAT formulae |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| Using a correct strategy for solving the problem by setting up two equations in \(a\) and \(u\) only and solving for either | M1 | AO3.1b |
| Equation in \(a\) and \(u\) only | M1 | AO3.1b |
| \(22 = 2u + \frac{1}{2}a \cdot 2^2\) | A1 | AO1.1b |
| Another equation in \(a\) and \(u\) only | M1 | AO3.1b |
| \(126 = 6u + \frac{1}{2}a \cdot 6^2\) | A1 | AO1.1b |
| \(5 \text{ m s}^{-2}\) | A1 | AO1.1b |
| \(6 \text{ m s}^{-1}\) | A1ft | AO1.1b — ft mark; do not award for absurd answers e.g. \(a > 15\), \(u > 50\) |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| Using correct strategy by obtaining actual speeds at two times and using \(a = (v-u)/t\) | M1 | AO3.1b |
| Actual speed at \(t=1\) = average speed over interval; \(22/2 = 11\) | M1, A1 | AO3.1b, AO1.1b |
| Actual speed at \(t=4\) = average speed over interval; \(104/4 = 26\) | M1, A1 | AO3.1b, AO1.1b |
| \(5 \text{ m s}^{-2}\) | A1 | AO1.1b |
| \(6 \text{ m s}^{-1}\) | A1ft | AO1.1b — do not award for absurd answers e.g. \(a > 15\), \(u > 50\) |
## Question 7(i)(ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| Using a correct strategy for solving the problem by setting up two equations in $a$ and $u$ only and solving for either | M1 | AO3.1b |
| Equation in $a$ and $u$ only | M1 | AO3.1b |
| $22 = 2u + \frac{1}{2}a \cdot 2^2$ | A1 | AO1.1b |
| Another equation in $a$ and $u$ only | M1 | AO3.1b |
| $126 = 6u + \frac{1}{2}a \cdot 6^2$ | A1 | AO1.1b |
| $5 \text{ m s}^{-2}$ | A1 | AO1.1b |
| $6 \text{ m s}^{-1}$ | A1ft | AO1.1b — ft mark; do not award for absurd answers e.g. $a > 15$, $u > 50$ |
**Alternative Method:**
| Answer/Working | Mark | Guidance |
|---|---|---|
| Using correct strategy by obtaining actual speeds at two times and using $a = (v-u)/t$ | M1 | AO3.1b |
| Actual speed at $t=1$ = average speed over interval; $22/2 = 11$ | M1, A1 | AO3.1b, AO1.1b |
| Actual speed at $t=4$ = average speed over interval; $104/4 = 26$ | M1, A1 | AO3.1b, AO1.1b |
| $5 \text{ m s}^{-2}$ | A1 | AO1.1b |
| $6 \text{ m s}^{-1}$ | A1ft | AO1.1b — do not award for absurd answers e.g. $a > 15$, $u > 50$ |
---\begin{enumerate}
\item A car is moving along a straight horizontal road with constant acceleration. There are three points $A , B$ and $C$, in that order, on the road, where $A B = 22 \mathrm {~m}$ and $B C = 104 \mathrm {~m}$. The car takes 2 s to travel from $A$ to $B$ and 4 s to travel from $B$ to $C$.
\end{enumerate}
Find\\
(i) the acceleration of the car,\\
(ii) the speed of the car at the instant it passes $A$.
\hfill \mbox{\textit{Edexcel AS Paper 2 Q7 [7]}}