| Exam Board | OCR MEI |
|---|---|
| Module | Further Mechanics Major (Further Mechanics Major) |
| Year | 2024 |
| Session | June |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions |
| Type | String becomes taut problem |
| Difficulty | Moderate -0.3 This is a straightforward application of conservation of momentum for an inelastic collision, followed by a basic impulse calculation using the change in momentum. Both parts require only direct substitution into standard formulas with no problem-solving insight needed, making it slightly easier than average but not trivial since it involves two bodies and requires careful identification of the system. |
| Spec | 6.03b Conservation of momentum: 1D two particles6.03f Impulse-momentum: relation |
| Answer | Marks |
|---|---|
| 1 (a) | 1200(1.5)=1200v+800v |
| v=0.9 | M1 |
| Answer | Marks |
|---|---|
| [2] | 3.3 |
| 1.1 | CLM soi – correct number of terms but allow sign |
| Answer | Marks |
|---|---|
| 1 (b) | I =800(0.9) or −I =1200(0.9)−1200(1.5) or −I =1200(0.9−1.5) |
| I =720 (N s) | M1 |
| Answer | Marks |
|---|---|
| [2] | 3.3 |
| 1.1 | Use of Impulse = change in momentum on either A or |
Question 1:
--- 1 (a) ---
1 (a) | 1200(1.5)=1200v+800v
v=0.9 | M1
A1
[2] | 3.3
1.1 | CLM soi – correct number of terms but allow sign
errors, and allow a slip in one value only
--- 1 (b) ---
1 (b) | I =800(0.9) or −I =1200(0.9)−1200(1.5) or −I =1200(0.9−1.5)
I =720 (N s) | M1
A1
[2] | 3.3
1.1 | Use of Impulse = change in momentum on either A or
B (so must be using the correct mass(es)), correct
number of terms using their v from part (a) but allow
sign errors
Final answer must be positive – but condone e.g.
‘I =1200(0.9)−1200(1.5)=−720 therefore 720’ for
full marksA car A of mass 1200 kg is about to tow another car B of mass 800 kg in a straight line along a horizontal road by means of a tow-rope attached between A and B. The tow-rope is modelled as being light and inextensible. Just before the tow-rope tightens, A is travelling at a speed of $1.5 \text{ m s}^{-1}$ and B is at rest. Just after the tow-rope tightens, both cars have a speed of $v \text{ m s}^{-1}$.
\begin{enumerate}[label=(\alph*)]
\item Find the value of $v$. [2]
\item Calculate the magnitude of the impulse on A when the tow-rope tightens. [2]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI Further Mechanics Major 2024 Q1 [4]}}