CAIE M2 2018 November — Question 5 8 marks

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2018
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 1
TypeConical pendulum – particle on horizontal surface
DifficultyStandard +0.3 This is a standard circular motion problem requiring resolution of forces and application of F=mv²/r. Part (i) involves straightforward force resolution with given speed; part (ii) requires setting up simultaneous equations with T=R condition. The geometry is clearly defined and the methods are routine for M2 level, making it slightly easier than average but still requiring careful multi-step working.
Spec6.05a Angular velocity: definitions6.05c Horizontal circles: conical pendulum, banked tracks

A particle \(P\) of mass \(0.1\text{ kg}\) is attached to one end of a light inextensible string of length \(0.5\text{ m}\). The other end of the string is attached to a fixed point \(A\). The particle \(P\) moves in a circle which has its centre \(O\) on a smooth horizontal surface \(0.3\text{ m}\) below \(A\). The tension in the string has magnitude \(T\text{ N}\) and the magnitude of the force exerted on \(P\) by the surface is \(R\text{ N}\).
  1. Given that the speed of \(P\) is \(1.5\text{ m s}^{-1}\), calculate \(T\) and \(R\). [4]
  2. Given instead that \(T = R\), calculate the angular speed of \(P\). [4]

Question 5:

AnswerMarks Guidance
5(i)0.1×1.52/0.4 = Tcosθ M1
Use Newton's Second Law horizontally
AnswerMarks Guidance
T = 0.703A1
R = 0.1g – TsinθM1 Resolve vertically for P
R = 0.578A1
4
AnswerMarks Guidance
QuestionAnswer Marks

AnswerMarks Guidance
5(ii)T + Tsinθ = 0.1g M1
T = 0.625A1
0.1ω 2×0.4 = 0.625cosθM1 Use Newton's Second Law horizontally
ω = 3.54 rad s–1A1
4
AnswerMarks Guidance
QuestionAnswer Marks
Question 5:
--- 5(i) ---
5(i) | 0.1×1.52/0.4 = Tcosθ | M1 | Note r = 0.4, cosθ = 0.8, sinθ = 0.6
Use Newton's Second Law horizontally
T = 0.703 | A1
R = 0.1g – Tsinθ | M1 | Resolve vertically for P
R = 0.578 | A1
4
Question | Answer | Marks | Guidance
--- 5(ii) ---
5(ii) | T + Tsinθ = 0.1g | M1 | Resolve vertically for P
T = 0.625 | A1
0.1ω 2×0.4 = 0.625cosθ | M1 | Use Newton's Second Law horizontally
ω = 3.54 rad s–1 | A1
4
Question | Answer | Marks | Guidance
A particle $P$ of mass $0.1\text{ kg}$ is attached to one end of a light inextensible string of length $0.5\text{ m}$. The other end of the string is attached to a fixed point $A$. The particle $P$ moves in a circle which has its centre $O$ on a smooth horizontal surface $0.3\text{ m}$ below $A$. The tension in the string has magnitude $T\text{ N}$ and the magnitude of the force exerted on $P$ by the surface is $R\text{ N}$.

\begin{enumerate}[label=(\roman*)]
\item Given that the speed of $P$ is $1.5\text{ m s}^{-1}$, calculate $T$ and $R$. [4]

\item Given instead that $T = R$, calculate the angular speed of $P$. [4]
\end{enumerate}

\hfill \mbox{\textit{CAIE M2 2018 Q5 [8]}}