Edexcel M1 2003 November — Question 7 16 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2003
SessionNovember
Marks16
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPulley systems
TypeHeavier particle hits ground, lighter continues upward - inclined plane involved
DifficultyStandard +0.3 This is a standard M1 pulley system question with straightforward application of Newton's second law to connected particles. Parts (a)-(c) involve routine equation setup and algebraic manipulation. Parts (e)-(f) use basic kinematics (SUVAT equations). While multi-part with several steps, each component follows textbook methods without requiring novel insight or complex problem-solving, making it slightly easier than the average A-level question.
Spec3.02d Constant acceleration: SUVAT formulae3.03k Connected particles: pulleys and equilibrium3.03l Newton's third law: extend to situations requiring force resolution

\includegraphics{figure_3} Figure 3 shows two particles \(A\) and \(B\), of mass \(m\) kg and 0.4 kg respectively, connected by a light inextensible string. Initially \(A\) is held at rest on a fixed smooth plane inclined at 30° to the horizontal. The string passes over a small light smooth pulley \(P\) fixed at the top of the plane. The section of the string from \(A\) to \(P\) is parallel to a line of greatest slope of the plane. The particle \(B\) hangs freely below \(P\). The system is released from rest with the string taut and \(B\) descends with acceleration \(\frac{1}{8}g\).
  1. Write down an equation of motion for \(B\). [2]
  2. Find the tension in the string. [2]
  3. Prove that \(m = \frac{16}{35}\). [4]
  4. State where in the calculations you have used the information that \(P\) is a light smooth pulley. [1]
On release, \(B\) is at a height of one metre above the ground and \(AP = 1.4\) m. The particle \(B\) strikes the ground and does not rebound.
  1. Calculate the speed of \(B\) as it reaches the ground. [2]
  2. Show that \(A\) comes to rest as it reaches \(P\). [5]
END

(a)
![Diagram showing forces]
AnswerMarks Guidance
\(0.4g - T = 0.4 \times \frac{1}{5}g\)M1 A1
(2)
(b)
AnswerMarks Guidance
\(T = \frac{8}{25}g\) or \(3.14\) or \(3.1\) NM1 A1
(2)
(c)
![Diagram showing inclined plane with tension and weight]
AnswerMarks Guidance
\(T - mg \sin 30° = m \times \frac{1}{5}g\)M1 A1
\(\rightarrow m = \underline{\frac{16}{35}}\) ★M1 A1
(4)
(d)
AnswerMarks Guidance
Same \(T\) for A & BB1 (1)
(e)
AnswerMarks Guidance
\(v^2 = 2 \times \frac{1}{5}g \times 1\)M1
\(v = \sqrt{\frac{2g}{5}} \approx 1.98\) or \(2\) m s\(^{-1}\) A1
(2)
(f)
AnswerMarks Guidance
A: \(-\frac{1}{2}mg = ma \Rightarrow a = -\frac{1}{2}g\)M1 A1
\(v^2 = \frac{2g}{5} - 2 \times \frac{1}{2}g \times 0.4\)M1 A1 ✓
\(\Rightarrow v = 0\) A1
(5)
Total: 16 marks
## (a)
![Diagram showing forces]
| |
$0.4g - T = 0.4 \times \frac{1}{5}g$ | M1 | A1
| | (2)

## (b)
$T = \frac{8}{25}g$ or $3.14$ or $3.1$ N | M1 | A1
| | (2)

## (c)
![Diagram showing inclined plane with tension and weight]
$T - mg \sin 30° = m \times \frac{1}{5}g$ | M1 | A1
$\rightarrow m = \underline{\frac{16}{35}}$ ★ | M1 | A1
| | (4)

## (d)
Same $T$ for A & B | B1 | (1)

## (e)
$v^2 = 2 \times \frac{1}{5}g \times 1$ | M1 |
$v = \sqrt{\frac{2g}{5}} \approx 1.98$ or $2$ m s$^{-1}$ | | A1
| | (2)

## (f)
A: $-\frac{1}{2}mg = ma \Rightarrow a = -\frac{1}{2}g$ | M1 | A1
$v^2 = \frac{2g}{5} - 2 \times \frac{1}{2}g \times 0.4$ | M1 | A1 ✓
$\Rightarrow v = 0$ | | A1
| | (5)

**Total: 16 marks**
\includegraphics{figure_3}

Figure 3 shows two particles $A$ and $B$, of mass $m$ kg and 0.4 kg respectively, connected by a light inextensible string. Initially $A$ is held at rest on a fixed smooth plane inclined at 30° to the horizontal. The string passes over a small light smooth pulley $P$ fixed at the top of the plane. The section of the string from $A$ to $P$ is parallel to a line of greatest slope of the plane. The particle $B$ hangs freely below $P$. The system is released from rest with the string taut and $B$ descends with acceleration $\frac{1}{8}g$.

\begin{enumerate}[label=(\alph*)]
\item Write down an equation of motion for $B$. [2]
\item Find the tension in the string. [2]
\item Prove that $m = \frac{16}{35}$. [4]
\item State where in the calculations you have used the information that $P$ is a light smooth pulley. [1]
\end{enumerate}

On release, $B$ is at a height of one metre above the ground and $AP = 1.4$ m. The particle $B$ strikes the ground and does not rebound.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{4}
\item Calculate the speed of $B$ as it reaches the ground. [2]
\item Show that $A$ comes to rest as it reaches $P$. [5]
\end{enumerate}

END

\hfill \mbox{\textit{Edexcel M1 2003 Q7 [16]}}