| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2012 |
| Session | January |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Newton's laws and connected particles |
| Type | Car towing trailer, horizontal |
| Difficulty | Moderate -0.8 This is a straightforward connected particles problem requiring application of Newton's second law to the system and individual components. The question provides the acceleration and asks students to find resistance and tension using standard F=ma equations with no conceptual complications or novel problem-solving required—easier than average A-level mechanics. |
| Spec | 3.03d Newton's second law: 2D vectors3.03k Connected particles: pulleys and equilibrium |
2. A car of mass 1000 kg is towing a caravan of mass 750 kg along a straight horizontal road. The caravan is connected to the car by a tow-bar which is parallel to the direction of motion of the car and the caravan. The tow-bar is modelled as a light rod. The engine of the car provides a constant driving force of 3200 N . The resistances to the motion of the car and the caravan are modelled as constant forces of magnitude 800 newtons and $R$ newtons respectively.
Given that the acceleration of the car and the caravan is $0.88 \mathrm {~ms} ^ { - 2 }$,
\begin{enumerate}[label=(\alph*)]
\item show that $R = 860$,
\item find the tension in the tow-bar.
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2012 Q2 [6]}}