| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Marks | 12 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Newton's laws and connected particles |
| Type | Atwood machine, vertical strings |
| Difficulty | Standard +0.3 This is a standard M1 pulley system question requiring Newton's second law applied to connected particles. Part (a) is routine bookwork with straightforward simultaneous equations. Part (b) adds a mild algebraic twist by relating two scenarios, but the method is still mechanical and predictable for this topic. Slightly easier than average due to its formulaic nature. |
| Spec | 3.03k Connected particles: pulleys and equilibrium3.03o Advanced connected particles: and pulleys |
| Answer | Marks | Guidance |
|---|---|---|
| (a) \(F = ma\) for each: \(2.4g - T = 2.4a\), \(T - 1.8g = 1.8a\) | Add: \(0.6g = 4.2a\) | \(a = \frac{1}{7}g = 1.4 \text{ ms}^{-1}\) |
| (b) Now \(1.8g - T = 1.8(0.7)\) so \(T = 16.38\), and \(T - mg = m(0.7)\) | \(10.5m = 16.38\) | \(m = 1.56\) |
(a) $F = ma$ for each: $2.4g - T = 2.4a$, $T - 1.8g = 1.8a$ | Add: $0.6g = 4.2a$ | $a = \frac{1}{7}g = 1.4 \text{ ms}^{-1}$ | $T = 20.2 \text{ N}$ | M1 A1 A1
(b) Now $1.8g - T = 1.8(0.7)$ so $T = 16.38$, and $T - mg = m(0.7)$ | $10.5m = 16.38$ | $m = 1.56$ | M1 A1 M1 A1 | **12 marks**Two metal weights $A$ and $B$, of masses 2.4 kg and 1.8 kg respectively, are attached to the ends of a light inextensible string which passes over a smooth fixed pulley so that the string hangs vertically on each side. The system is released from rest with the string taut.
\begin{enumerate}[label=(\alph*)]
\item Calculate the acceleration of each weight and the tension in the string. [6 marks]
\end{enumerate}
$A$ is now replaced by a different weight of mass $m$ kg, where $m < 1.8$, and the system is again released from rest. The magnitude of the acceleration has half of its previous value.
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Calculate the value of $m$. [6 marks]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 Q5 [12]}}