Edexcel M1 2019 January — Question 3 7 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2019
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicNewton's laws and connected particles
TypeLift with passenger or load
DifficultyModerate -0.8 This is a straightforward application of Newton's second law to two connected bodies with given acceleration. Students simply write F=ma twice (once for person, once for lift), then solve two simple linear equations. No problem-solving insight required—purely routine mechanics with clear setup and standard method.
Spec3.03c Newton's second law: F=ma one dimension3.03d Newton's second law: 2D vectors

3. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0d5a56ba-6a33-4dc8-b612-d2957211124f-08_387_204_251_872} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} A lift of mass \(M \mathrm {~kg}\) is being raised by a vertical cable attached to the top of the lift. A person of mass \(m \mathrm {~kg}\) stands on the floor inside the lift, as shown in Figure 1. The lift ascends vertically with constant acceleration \(1.4 \mathrm {~m} \mathrm {~s} ^ { - 2 }\). The tension in the cable is 2800 N and the person experiences a constant normal reaction of magnitude 560 N from the floor of the lift. The cable is modelled as being light and inextensible, the person is modelled as a particle and air resistance is negligible.
  1. Write down an equation of motion for the person only.
  2. Write down an equation of motion for the lift only.
  3. Hence, or otherwise, find
    1. the value of \(m\),
    2. the value of \(M\).

Question 3:
Part (a)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(560 - mg = 1.4m\)M1 A1 Equation of motion for person only; at least one value (560 or 1.4) substituted. Credit only if appears in (a)
Part (b)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(2800 - Mg - 560 = 1.4M\)M1 A1 Equation of motion for lift only; at least one value (2800, 560 or 1.4) substituted. Credit only if appears in (b)
Part (c)(i) and (ii)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(560 = 11.2m\)DM1 Dependent on appropriate previous M mark; solving one of their equations
\(m = 50\)A1
\(2240 = 11.2M\)
\(M = 200\)A1
# Question 3:

## Part (a)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $560 - mg = 1.4m$ | M1 A1 | Equation of motion for person only; at least one value (560 or 1.4) substituted. Credit only if appears in (a) |

## Part (b)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $2800 - Mg - 560 = 1.4M$ | M1 A1 | Equation of motion for lift only; at least one value (2800, 560 or 1.4) substituted. Credit only if appears in (b) |

## Part (c)(i) and (ii)
| Answer/Working | Marks | Guidance |
|---|---|---|
| $560 = 11.2m$ | DM1 | Dependent on appropriate previous M mark; solving one of their equations |
| $m = 50$ | A1 | |
| $2240 = 11.2M$ | | |
| $M = 200$ | A1 | |

---
3.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{0d5a56ba-6a33-4dc8-b612-d2957211124f-08_387_204_251_872}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

A lift of mass $M \mathrm {~kg}$ is being raised by a vertical cable attached to the top of the lift. A person of mass $m \mathrm {~kg}$ stands on the floor inside the lift, as shown in Figure 1. The lift ascends vertically with constant acceleration $1.4 \mathrm {~m} \mathrm {~s} ^ { - 2 }$. The tension in the cable is 2800 N and the person experiences a constant normal reaction of magnitude 560 N from the floor of the lift. The cable is modelled as being light and inextensible, the person is modelled as a particle and air resistance is negligible.
\begin{enumerate}[label=(\alph*)]
\item Write down an equation of motion for the person only.
\item Write down an equation of motion for the lift only.
\item Hence, or otherwise, find
\begin{enumerate}[label=(\roman*)]
\item the value of $m$,
\item the value of $M$.
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2019 Q3 [7]}}