| Exam Board | WJEC |
|---|---|
| Module | Unit 2 (Unit 2) |
| Session | Specimen |
| Marks | 8 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Pulley systems |
| Type | Variable mass or unknown mass |
| Difficulty | Standard +0.3 This is a standard two-body connected particles problem requiring Newton's second law applied to both masses separately, then solving simultaneous equations. The setup is clearly described, the acceleration is given (not derived), and the method is routine A-level mechanics. Part (b) tests understanding of modeling assumptions, which is straightforward. Slightly easier than average due to the given acceleration and clear problem structure. |
| Spec | 3.03k Connected particles: pulleys and equilibrium3.03l Newton's third law: extend to situations requiring force resolution |
A truck of mass 180 kg runs on smooth horizontal rails. A light inextensible rope is attached to the front of the truck. The rope runs parallel to the rails until it passes over a light smooth pulley. The rest of the rope hangs down a vertical shaft. When the truck is required to move, a load of $M$ kg is attached to the end of the rope in the shaft and the brakes are then released.
\begin{enumerate}[label=(\alph*)]
\item Find the tension in the rope when the truck and the load move with an acceleration of magnitude 0.8 ms$^{-2}$ and calculate the corresponding value of $M$. [5]
\item In addition to the assumptions given in the question, write down one further assumption that you have made in your solution to this problem and explain how that assumption affects both of your answers. [3]
\end{enumerate}
\hfill \mbox{\textit{WJEC Unit 2 Q9 [8]}}