AQA Further AS Paper 2 Mechanics 2024 June — Question 9 6 marks

Exam BoardAQA
ModuleFurther AS Paper 2 Mechanics (Further AS Paper 2 Mechanics)
Year2024
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 1
TypeRotating disc with friction
DifficultyStandard +0.3 This is a straightforward circular motion problem requiring application of F=mrω² with friction providing centripetal force. The calculation is direct with given values, requiring only unit conversion (grams to kg, cm to m) and rearrangement of a standard formula. While it's Further Maths content, the problem-solving is routine with no novel insight needed, making it slightly easier than average overall.
Spec6.05b Circular motion: v=r*omega and a=v^2/r6.05c Horizontal circles: conical pendulum, banked tracks

A small coin is placed at a point \(C\) on a rough horizontal turntable, with centre \(O\), as shown in the diagram below. \includegraphics{figure_9} The mass of the coin is 3.6 grams. The distance \(OC\) is 20 cm The turntable rotates about a vertical axis through \(O\), with constant angular speed \(\omega\) radians per second.
  1. Draw a diagram to show all the forces acting on the coin. [1 mark]
  2. The maximum value of friction is 0.01 newtons and the coin does not slip during the motion. Find the maximum value of \(\omega\) Give your answer to two significant figures. [4 marks]
  3. State one modelling assumption you have made to answer part (b). [1 mark]

Question 9:

AnswerMarks
9(a)Draws a correct force diagram
showing weight, normal reaction
AnswerMarks Guidance
and friction and no other forces.1.1b B1
Subtotal1
QMarking instructions AO

AnswerMarks
9(b)Recalls a correct expression for
the acceleration or force
AnswerMarks Guidance
towards O1.2 B1
F = mrω2
0.01 = (0.0036)(0.2)ω2
0.01
ω =
0.0036×0.2
ω = 3.7
Forms the equation F = mrω2 or
mv2
F =
AnswerMarks Guidance
r3.3 M1
Obtains a correct equation in ω
AnswerMarks Guidance
or v1.1b A1
Obtains ω = 3.7
AnswerMarks Guidance
AWRT 3.71.1b A1
Subtotal4
QMarking instructions AO

AnswerMarks
9(c)States an appropriate modelling
assumption.
Eg
The coin is modelled as a
particle.
The radius is the distance to the
centre of mass of the coin from
O
AnswerMarks Guidance
No air resistance forces.3.5a E1
Subtotal1
Question total6
Question Paper total40
Question 9:
--- 9(a) ---
9(a) | Draws a correct force diagram
showing weight, normal reaction
and friction and no other forces. | 1.1b | B1
Subtotal | 1
Q | Marking instructions | AO | Marks | Typical solution
--- 9(b) ---
9(b) | Recalls a correct expression for
the acceleration or force
towards O | 1.2 | B1 | a = rω2
F = mrω2
0.01 = (0.0036)(0.2)ω2
0.01
ω =
0.0036×0.2
ω = 3.7
Forms the equation F = mrω2 or
mv2
F =
r | 3.3 | M1
Obtains a correct equation in ω
or v | 1.1b | A1
Obtains ω = 3.7
AWRT 3.7 | 1.1b | A1
Subtotal | 4
Q | Marking instructions | AO | Marks | Typical solution
--- 9(c) ---
9(c) | States an appropriate modelling
assumption.
Eg
The coin is modelled as a
particle.
The radius is the distance to the
centre of mass of the coin from
O
No air resistance forces. | 3.5a | E1 | The coin is modelled as a particle.
Subtotal | 1
Question total | 6
Question Paper total | 40
A small coin is placed at a point $C$ on a rough horizontal turntable, with centre $O$, as shown in the diagram below.

\includegraphics{figure_9}

The mass of the coin is 3.6 grams.

The distance $OC$ is 20 cm

The turntable rotates about a vertical axis through $O$, with constant angular speed $\omega$ radians per second.

\begin{enumerate}[label=(\alph*)]
\item Draw a diagram to show all the forces acting on the coin. [1 mark]

\item The maximum value of friction is 0.01 newtons and the coin does not slip during the motion.

Find the maximum value of $\omega$

Give your answer to two significant figures. [4 marks]

\item State one modelling assumption you have made to answer part (b). [1 mark]
\end{enumerate}

\hfill \mbox{\textit{AQA Further AS Paper 2 Mechanics 2024 Q9 [6]}}