Edexcel M1 2020 June — Question 3 8 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2020
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMotion on a slope
TypeRange of forces for equilibrium
DifficultyStandard +0.3 This is a standard M1 equilibrium on a slope question with friction. Part (a) is straightforward resolution perpendicular to the plane. Parts (b) and (c) require understanding that friction can act in either direction (limiting equilibrium cases), which is a key M1 concept but well-practiced. The tan α = 3/4 setup is typical, and all three parts follow standard procedures with no novel insight required. Slightly easier than average due to clear structure and routine application of methods.
Spec3.03n Equilibrium in 2D: particle under forces3.03t Coefficient of friction: F <= mu*R model3.03v Motion on rough surface: including inclined planes

3. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{05cf68a3-1ba4-487f-9edd-48a246f4194f-08_259_597_214_678} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} A particle of mass 10 kg is placed on a fixed rough inclined plane. The plane is inclined to the horizontal at an angle \(\alpha\), where \(\tan \alpha = \frac { 3 } { 4 }\). The particle is held in equilibrium by a force of magnitude \(P\) newtons, which acts up the plane, as shown in Figure 1. The line of action of the force lies in a vertical plane that contains a line of greatest slope of the plane. The coefficient of friction between the particle and the plane is \(\frac { 1 } { 2 }\).
  1. Find the normal reaction between the particle and the plane.
  2. Find the greatest possible value of \(P\).
  3. Find the least possible value of \(P\). DO NOT WRITEIN THIS AREA
    VIXV SIHIANI III IM IONOOVIAV SIHI NI JYHAM ION OOVI4V SIHI NI JLIYM ION OO

Question 3:
Part (a):
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(R = 10g\cos\alpha\)M1 Allow sin/cos confusion
\(= 78.4\) or \(78\) NA1 Allow \(8g\)
Part (b):
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(F = 0.5R\)B1 \(F = 0.5R\) seen anywhere
\(P = 10g\sin\alpha + F\)M1 A1 Correct number of terms, with \(10g\) resolved
\(= 98\)A1 Allow \(10g\). For inequality never becoming equation: Max M1A1A0 for \(P \leq 10g\sin\alpha + F\)
Part (c):
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(P = 10g\sin\alpha - F\)M1 Correct number of terms, with \(10g\) resolved
\(= 19.6\) or \(20\)A1 Allow \(2g\). For inequality never becoming equation: Max M1A0
## Question 3:

### Part (a):
| Answer/Working | Marks | Guidance |
|---|---|---|
| $R = 10g\cos\alpha$ | M1 | Allow sin/cos confusion |
| $= 78.4$ or $78$ N | A1 | Allow $8g$ |

### Part (b):
| Answer/Working | Marks | Guidance |
|---|---|---|
| $F = 0.5R$ | B1 | $F = 0.5R$ seen anywhere |
| $P = 10g\sin\alpha + F$ | M1 A1 | Correct number of terms, with $10g$ resolved |
| $= 98$ | A1 | Allow $10g$. For inequality never becoming equation: Max M1A1A0 for $P \leq 10g\sin\alpha + F$ |

### Part (c):
| Answer/Working | Marks | Guidance |
|---|---|---|
| $P = 10g\sin\alpha - F$ | M1 | Correct number of terms, with $10g$ resolved |
| $= 19.6$ or $20$ | A1 | Allow $2g$. For inequality never becoming equation: Max M1A0 |

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3.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{05cf68a3-1ba4-487f-9edd-48a246f4194f-08_259_597_214_678}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

A particle of mass 10 kg is placed on a fixed rough inclined plane. The plane is inclined to the horizontal at an angle $\alpha$, where $\tan \alpha = \frac { 3 } { 4 }$. The particle is held in equilibrium by a force of magnitude $P$ newtons, which acts up the plane, as shown in Figure 1. The line of action of the force lies in a vertical plane that contains a line of greatest slope of the plane. The coefficient of friction between the particle and the plane is $\frac { 1 } { 2 }$.
\begin{enumerate}[label=(\alph*)]
\item Find the normal reaction between the particle and the plane.
\item Find the greatest possible value of $P$.
\item Find the least possible value of $P$.

DO NOT WRITEIN THIS AREA\\

\begin{center}
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VIXV SIHIANI III IM IONOO & VIAV SIHI NI JYHAM ION OO & VI4V SIHI NI JLIYM ION OO \\
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\end{tabular}
\end{center}

\begin{center}

\end{center}
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2020 Q3 [8]}}