| Exam Board | AQA |
|---|---|
| Module | Paper 2 (Paper 2) |
| Year | 2021 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Newton's laws and connected particles |
| Type | Car towing trailer, horizontal |
| Difficulty | Easy -1.8 This is a very straightforward application of Newton's first law to connected particles at constant velocity. Part (a) requires only recognizing equilibrium (forces balance) and simple arithmetic (T = 40 - 12 = 28N), while part (b) asks for a standard assumption. This is simpler than typical mechanics questions as it involves no calculation complexity, no acceleration, and tests only basic conceptual understanding. |
| Spec | 3.03b Newton's first law: equilibrium3.03m Equilibrium: sum of resolved forces = 0 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(T = 12\) | B1 (AO2.2a) | Deduces \(T=12\) |
| Constant speed means forces on trailer are in equilibrium; \(T\) must balance resistant force | E1 (AO2.4) | States clear reason; no resultant force since no acceleration |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| The rod remains horizontal | E1 (AO3.5b) | States one valid assumption e.g. rod is rigid; rod lies parallel to direction of travel; rod is inextensible |
| Answer | Marks | Guidance |
|---|---|---|
| Answer/Working | Mark | Guidance |
| \(40 = T + R\); PI by \(R = 28\) | M1 (AO3.3) | Forms equilibrium equation of forces acting on cyclist and cycle |
| \(R = 28\text{ N}\) | A1 (AO3.2a) | Must state units |
## Question 15(a):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $T = 12$ | B1 (AO2.2a) | Deduces $T=12$ |
| Constant speed means forces on trailer are in equilibrium; $T$ must balance resistant force | E1 (AO2.4) | States clear reason; no resultant force since no acceleration |
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## Question 15(b):
| Answer/Working | Mark | Guidance |
|---|---|---|
| The rod remains horizontal | E1 (AO3.5b) | States one valid assumption e.g. rod is rigid; rod lies parallel to direction of travel; rod is inextensible |
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## Question 15(c):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $40 = T + R$; PI by $R = 28$ | M1 (AO3.3) | Forms equilibrium equation of forces acting on cyclist and cycle |
| $R = 28\text{ N}$ | A1 (AO3.2a) | Must state units |
---15 A cyclist is towing a trailer behind her bicycle.
She is riding along a straight, horizontal path at a constant speed.\\
\includegraphics[max width=\textwidth, alt={}, center]{b7df05bf-f3fc-4705-a13c-6b562896fa9f-22_371_723_447_657}
A tension of $T$ newtons acts on the connecting rod between the bicycle and the trailer.\\
The cyclist is causing a constant driving force of 40 N to be applied whilst pedalling forwards on her bicycle.
The constant resistance force acting on the trailer is 12 N\\
15
\begin{enumerate}[label=(\alph*)]
\item State the value of $T$ giving a clear reason for your answer.\\
15
\item State one assumption you have made in reaching your answer to part (a).
\end{enumerate}
\hfill \mbox{\textit{AQA Paper 2 2021 Q15 [5]}}