| Exam Board | OCR |
|---|---|
| Module | M1 (Mechanics 1) |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Forces, equilibrium and resultants |
| Type | Connected particles via tow-bar on horizontal surface |
| Difficulty | Moderate -0.8 This is a straightforward two-body mechanics problem requiring only Newton's second law (F=ma) applied twice. Students identify forces, apply F=ma to the trailer (part i) and then to the car (part ii). No problem-solving insight needed—just systematic application of a standard method with clear numerical values provided. |
| Spec | 3.03c Newton's second law: F=ma one dimension3.03k Connected particles: pulleys and equilibrium |
A trailer of mass $600$ kg is attached to a car of mass $1100$ kg by a light rigid horizontal tow-bar. The car and trailer are travelling along a horizontal straight road with acceleration $0.8$ m s$^{-2}$.
\begin{enumerate}[label=(\roman*)]
\item Given that the force exerted on the trailer by the tow-bar is $700$ N, find the resistance to motion of the trailer. [4]
\item Given also that the driving force of the car is $2100$ N, find the resistance to motion of the car. [3]
\end{enumerate}
\hfill \mbox{\textit{OCR M1 Q1 [7]}}