| Exam Board | OCR MEI |
|---|---|
| Module | Further Mechanics B AS (Further Mechanics B AS) |
| Session | Specimen |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Circular Motion 1 |
| Type | Angular speed conversion and basic circular motion quantities |
| Difficulty | Moderate -0.8 This is a straightforward circular motion question requiring standard conversions and direct application of F=mrω². Part (i)(A) is routine unit conversion, (i)(B) is a one-step formula application, and (ii) tests basic understanding that smoothness eliminates friction. No problem-solving or novel insight required; easier than average A-level. |
| Spec | 3.03b Newton's first law: equilibrium6.05a Angular velocity: definitions6.05b Circular motion: v=r*omega and a=v^2/r |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | (i) | (A) |
| Answer | Marks | Guidance |
|---|---|---|
| (12.566…) | B1 | |
| [1] | 1.1 | |
| 2 | (i) | (B) |
| Answer | Marks |
|---|---|
| [towards the centre] | M1 |
| Answer | Marks |
|---|---|
| [4] | 1.1a |
| Answer | Marks |
|---|---|
| 1.1 | N |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | (ii) | Otherwise there would be a tangential (transverse) |
| force as well as the central force | E1 | |
| [1] | 3.5b | M |
Question 2:
2 | (i) | (A) | 1
120 rev min -1 gives (cid:90)(cid:32)120(cid:117)2(cid:117)(cid:83)(cid:117) (cid:32)4(cid:83) rad s -1
60
(12.566…) | B1
[1] | 1.1
2 | (i) | (B) | Accn towards centre
so 2.5(cid:117)(cid:11)4(cid:83)(cid:12)2 (cid:32)40(cid:83)2 m s -2 (394.78…)
Using N2L
Radial force is 0.2(cid:117)40(cid:83)2 (cid:32)8(cid:83)2N (78.95…)
[towards the centre] | M1
A1
M1
A1
[4] | 1.1a
1.1
3.4
1.1 | N
Use (m)r(cid:90)2 (m not required)
May be implied
E
Use of N2L
cao
2 | (ii) | Otherwise there would be a tangential (transverse)
force as well as the central force | E1
[1] | 3.5b | M2 A smooth wire is bent to form a circle of radius 2.5 m ; the circle is in a horizontal plane. A small ring of mass 0.2 kg is travelling round the wire.
\begin{enumerate}[label=(\roman*)]
\item At one instant the ring is travelling at an angular speed of 120 revolutions per minute.\\
(A) Calculate the angular speed in radians per second.\\
(B) Calculate the component towards the centre of the circle of the force exerted on the ring by the wire.
\item Why must the contact between the wire and the ring be smooth if your answer to part (i) ( $B$ ) is also the total horizontal component of the force exerted on the ring by the wire?
\end{enumerate}
\hfill \mbox{\textit{OCR MEI Further Mechanics B AS Q2 [6]}}