| Exam Board | AQA |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2012 |
| Session | June |
| Marks | 15 |
| Paper | Download PDF ↗ |
| Topic | Pulley systems |
| Type | Particle on smooth horizontal surface, particle hanging |
| Difficulty | Standard +0.3 This is a standard M1 pulley problem with connected particles requiring Newton's second law applied to two bodies, followed by friction calculations. The multi-part structure guides students through the solution methodically (smooth case first, then rough surface), and all techniques are routine for M1 level. While it requires careful bookkeeping of forces and simultaneous equations, it involves no novel insight or particularly challenging conceptual leaps—slightly easier than average due to its structured, scaffolded approach. |
| Spec | 3.03f Weight: W=mg3.03m Equilibrium: sum of resolved forces = 03.03n Equilibrium in 2D: particle under forces3.03t Coefficient of friction: F <= mu*R model3.03v Motion on rough surface: including inclined planes |
5 A block, of mass 12 kg , lies on a horizontal surface. The block is attached to a particle, of mass 18 kg , by a light inextensible string which passes over a smooth fixed peg. Initially, the block is held at rest so that the string supports the particle, as shown in the diagram.\\
\includegraphics[max width=\textwidth, alt={}, center]{828e8db1-efcf-4878-8292-ba5bbd80115c-3_346_716_1557_715}
The block is then released.
\begin{enumerate}[label=(\alph*)]
\item Assuming that the surface is smooth, use two equations of motion to find the magnitude of the acceleration of the block and particle.
\item In reality, the surface is rough and the acceleration of the block is $3 \mathrm {~ms} ^ { - 2 }$.
\begin{enumerate}[label=(\roman*)]
\item Find the tension in the string.
\item Calculate the magnitude of the normal reaction force acting on the block.
\item Find the coefficient of friction between the block and the surface.
\end{enumerate}\item State two modelling assumptions, other than those given, that you have made in answering this question.
\end{enumerate}
\hfill \mbox{\textit{AQA M1 2012 Q5 [15]}}