OCR MEI Further Mechanics Major Specimen — Question 4 6 marks

Exam BoardOCR MEI
ModuleFurther Mechanics Major (Further Mechanics Major)
SessionSpecimen
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 1
TypeVertical circle – surface contact (sphere/track, leaving surface)
DifficultyStandard +0.3 This is a standard particle-on-sphere problem requiring energy conservation and circular motion dynamics—both routine Further Maths techniques. The question guides students through each step explicitly, and the final part involves straightforward substitution. While it requires multiple concepts, the approach is well-established and no novel insight is needed.
Spec3.03i Normal reaction force6.02i Conservation of energy: mechanical energy principle6.05d Variable speed circles: energy methods

A fixed smooth sphere has centre O and radius \(a\). A particle P of mass \(m\) is placed at the highest point of the sphere and given an initial horizontal speed \(u\). For the first part of its motion, P remains in contact with the sphere and has speed \(v\) when OP makes an angle \(\theta\) with the upward vertical. This is shown in Fig. 4. \includegraphics{figure_4}
  1. By considering the energy of P, show that \(v^2 = u^2 + 2ga(1 - \cos\theta)\). [2]
  2. Show that the magnitude of the normal contact force between the sphere and particle P is $$mg(3\cos\theta - 2) - \frac{mv^2}{a}.$$ [2]
The particle loses contact with the sphere when \(\cos\theta = \frac{3}{4}\).
  1. Find an expression for \(u\) in terms of \(a\) and \(g\). [2]

Question 4:
AnswerMarks Guidance
4(i) Conservation of energy:
1 1
mv2 (cid:32) mu2 (cid:14)mga(cid:11)1(cid:16)cos(cid:84)(cid:12)
2 2
AnswerMarks
v2 (cid:32)u2 (cid:14)2ga(1(cid:16)cos(cid:84)) AGM1
A1
AnswerMarks
[2]3.4
1.1Using conservation of energy or
work-energy equation
Correct use of c.o.e. leading to
given answer
AnswerMarks Guidance
4(ii) mv2
N2L: R(cid:32)mgcos(cid:84)(cid:16)
a
m
(cid:32)mgcos(cid:84)(cid:16) (cid:11) u2 (cid:14)2ga(cid:11)1(cid:16)cos(cid:84)(cid:12)(cid:12)
a
mu2
R(cid:32)mg(cid:11)3cos(cid:84)(cid:16)2(cid:12)(cid:16) . AG
AnswerMarks
aB1
A1
AnswerMarks
[2]3.4
1.1N
CElearly shown
AnswerMarks Guidance
MN2L is Newton's second law
4(iii) 3
Use R = 0, cos(cid:84)(cid:32)
4
1
u(cid:32) ga
AnswerMarks
2M1
A1
AnswerMarks
[2]I
C
3.1b
AnswerMarks
1.1Both used
Question 4:
4 | (i) | Conservation of energy:
1 1
mv2 (cid:32) mu2 (cid:14)mga(cid:11)1(cid:16)cos(cid:84)(cid:12)
2 2
v2 (cid:32)u2 (cid:14)2ga(1(cid:16)cos(cid:84)) AG | M1
A1
[2] | 3.4
1.1 | Using conservation of energy or
work-energy equation
Correct use of c.o.e. leading to
given answer
4 | (ii) | mv2
N2L: R(cid:32)mgcos(cid:84)(cid:16)
a
m
(cid:32)mgcos(cid:84)(cid:16) (cid:11) u2 (cid:14)2ga(cid:11)1(cid:16)cos(cid:84)(cid:12)(cid:12)
a
mu2
R(cid:32)mg(cid:11)3cos(cid:84)(cid:16)2(cid:12)(cid:16) . AG
a | B1
A1
[2] | 3.4
1.1 | N
CElearly shown
M | N2L is Newton's second law
4 | (iii) | 3
Use R = 0, cos(cid:84)(cid:32)
4
1
u(cid:32) ga
2 | M1
A1
[2] | I
C
3.1b
1.1 | Both used
A fixed smooth sphere has centre O and radius $a$. A particle P of mass $m$ is placed at the highest point of the sphere and given an initial horizontal speed $u$.

For the first part of its motion, P remains in contact with the sphere and has speed $v$ when OP makes an angle $\theta$ with the upward vertical. This is shown in Fig. 4.

\includegraphics{figure_4}

\begin{enumerate}[label=(\roman*)]
\item By considering the energy of P, show that $v^2 = u^2 + 2ga(1 - \cos\theta)$. [2]
\item Show that the magnitude of the normal contact force between the sphere and particle P is
$$mg(3\cos\theta - 2) - \frac{mv^2}{a}.$$ [2]
\end{enumerate}

The particle loses contact with the sphere when $\cos\theta = \frac{3}{4}$.

\begin{enumerate}[label=(\roman*)]
\setcounter{enumi}{2}
\item Find an expression for $u$ in terms of $a$ and $g$. [2]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Further Mechanics Major  Q4 [6]}}