AQA AS Paper 1 2019 June — Question 14 7 marks

Exam BoardAQA
ModuleAS Paper 1 (AS Paper 1)
Year2019
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors Introduction & 2D
TypeNewton's second law with vector forces (find acceleration or force)
DifficultyModerate -0.8 This is a straightforward AS-level mechanics question testing basic vector operations (distance formula), equilibrium of forces (simple addition), and constant acceleration kinematics. All parts are routine applications of standard formulas with no problem-solving insight required—easier than the typical A-level question which would involve more integration of concepts or multi-step reasoning.
Spec1.10f Distance between points: using position vectors3.02d Constant acceleration: SUVAT formulae3.03b Newton's first law: equilibrium3.03c Newton's second law: F=ma one dimension

Two particles, \(A\) and \(B\), lie at rest on a smooth horizontal plane. \(A\) has position vector \(\mathbf{r}_A = (13\mathbf{i} - 22\mathbf{j})\) metres \(B\) has position vector \(\mathbf{r}_B = (3\mathbf{i} + 2\mathbf{j})\) metres
  1. Calculate the distance between \(A\) and \(B\). [2 marks]
  2. Three forces, \(\mathbf{F}_1\), \(\mathbf{F}_2\) and \(\mathbf{F}_3\) are applied to particle \(A\), where \(\mathbf{F}_1 = (-2\mathbf{i} + 4\mathbf{j})\) newtons \(\mathbf{F}_2 = (6\mathbf{i} - 10\mathbf{j})\) newtons Given that \(A\) remains at rest, explain why \(\mathbf{F}_3 = (-4\mathbf{i} + 6\mathbf{j})\) newtons [1 mark]
  3. A force of \((5\mathbf{i} - 12\mathbf{j})\) newtons, is applied to \(B\), so that \(B\) moves, from rest, in a straight line towards \(A\). \(B\) has a mass of \(0.8 \text{kg}\)
    1. Show that the acceleration of \(B\) towards \(A\) is \(16.25 \text{m s}^{-2}\) [2 marks]
    2. Hence, find the time taken for \(B\) to reach \(A\). Give your answer to two significant figures. [2 marks]

Question 14:

AnswerMarks
14(a)Condone omission of units
throughout this question
Calculates the magnitude of AB
AnswerMarks Guidance
Ignore one sign error.1.1a M1
2 2
�(13−3) +(−22−2)
= 26
AnswerMarks Guidance
Obtains correct distance.1.1b A1

AnswerMarks
14(b)Explains that remains at rest
implies resultant force = 0 and
shows F + F𝐴𝐴 + F = 0
1 2 3
or shows addition of F and F and
1 2
states that F is the opposite
AnswerMarks Guidance
32.4 E1
3

(c)(i) ---
14
AnswerMarks
(c)(i)Calculates magnitude of given
force
Or uses Newton’s second law to
AnswerMarks Guidance
obtain a = 6.25i – 15j1.1a M1
𝑎𝑎 = 16.25
AnswerMarks Guidance
Completes calculation correctly AG2.1 R1

(c)(ii) ---
14
AnswerMarks Guidance
(c)(ii)Uses appropriate suvat equation
with a = 16.25 and their s used3.3 M1
26 = 0.5×16.2 5×𝑡𝑡
2
𝑡𝑡t == 13.8.2
Solves to find the correct value of
AnswerMarks Guidance
time to 2sf1.1b A1
Total7
QMarking Instructions AO
Question 14:
--- 14(a) ---
14(a) | Condone omission of units
throughout this question
Calculates the magnitude of AB
Ignore one sign error. | 1.1a | M1 | Distance =
2 2
�(13−3) +(−22−2)
= 26
Obtains correct distance. | 1.1b | A1
--- 14(b) ---
14(b) | Explains that remains at rest
implies resultant force = 0 and
shows F + F𝐴𝐴 + F = 0
1 2 3
or shows addition of F and F and
1 2
states that F is the opposite
3 | 2.4 | E1 | s(o− F 2𝐢𝐢 i+s t4h𝐣𝐣e) o+pp(o 6 s 𝐢𝐢 i − te 1 = 0 𝐣𝐣 -)4i = +6 4 j 𝐢𝐢 −6𝐣𝐣
3
--- 14
(c)(i) ---
14
(c)(i) | Calculates magnitude of given
force
Or uses Newton’s second law to
obtain a = 6.25i – 15j | 1.1a | M1 | 1|𝑭𝑭3 |== 01.83a
𝑎𝑎 = 16.25
Completes calculation correctly AG | 2.1 | R1
--- 14
(c)(ii) ---
14
(c)(ii) | Uses appropriate suvat equation
with a = 16.25 and their s used | 3.3 | M1 | 2
26 = 0.5×16.2 5×𝑡𝑡
2
𝑡𝑡t == 13.8.2
Solves to find the correct value of
time to 2sf | 1.1b | A1
Total | 7
Q | Marking Instructions | AO | Marks | Typical Solution
Two particles, $A$ and $B$, lie at rest on a smooth horizontal plane.

$A$ has position vector $\mathbf{r}_A = (13\mathbf{i} - 22\mathbf{j})$ metres
$B$ has position vector $\mathbf{r}_B = (3\mathbf{i} + 2\mathbf{j})$ metres

\begin{enumerate}[label=(\alph*)]
\item Calculate the distance between $A$ and $B$.
[2 marks]

\item Three forces, $\mathbf{F}_1$, $\mathbf{F}_2$ and $\mathbf{F}_3$ are applied to particle $A$, where

$\mathbf{F}_1 = (-2\mathbf{i} + 4\mathbf{j})$ newtons

$\mathbf{F}_2 = (6\mathbf{i} - 10\mathbf{j})$ newtons

Given that $A$ remains at rest, explain why $\mathbf{F}_3 = (-4\mathbf{i} + 6\mathbf{j})$ newtons
[1 mark]

\item A force of $(5\mathbf{i} - 12\mathbf{j})$ newtons, is applied to $B$, so that $B$ moves, from rest, in a straight line towards $A$.

$B$ has a mass of $0.8 \text{kg}$

\begin{enumerate}[label=(\roman*)]
\item Show that the acceleration of $B$ towards $A$ is $16.25 \text{m s}^{-2}$
[2 marks]

\item Hence, find the time taken for $B$ to reach $A$.

Give your answer to two significant figures.
[2 marks]
\end{enumerate}
\end{enumerate}

\hfill \mbox{\textit{AQA AS Paper 1 2019 Q14 [7]}}