| Exam Board | CAIE |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2020 |
| Session | November |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions |
| Type | Coalescence collision |
| Difficulty | Moderate -0.8 This is a straightforward application of conservation of momentum for a perfectly inelastic collision (coalescing particles), followed by a standard kinetic energy calculation. Both parts require direct formula application with no problem-solving insight or geometric reasoning—simpler than the average A-level question which typically requires multiple techniques or some conceptual understanding. |
| Spec | 6.02d Mechanical energy: KE and PE concepts6.03b Conservation of momentum: 1D two particles |
| Answer | Marks | Guidance |
|---|---|---|
| 1(a) | 6 × 2.5 = 2.5v + 5v | M1 |
| v = 2 ms–1 | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| 1(b) | Use KE = ½ mv2 either before or after collision | M1 |
| Answer | Marks | Guidance |
|---|---|---|
| KE(after) = 0.5 × 7.5 × 22 | A1 FT | Both correct FT on v |
| Loss of KE = 30 J | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| Question | Answer | Marks |
Question 1:
--- 1(a) ---
1(a) | 6 × 2.5 = 2.5v + 5v | M1 | Apply conservation of momentum, 3 terms implied
v = 2 ms–1 | A1
2
--- 1(b) ---
1(b) | Use KE = ½ mv2 either before or after collision | M1 | Allow this for either particle
KE(before) = 0.5 × 2.5 × 62
KE(after) = 0.5 × 7.5 × 22 | A1 FT | Both correct FT on v
Loss of KE = 30 J | A1
3
Question | Answer | Marks | GuidanceA particle $B$ of mass 5 kg is at rest on a smooth horizontal table. A particle $A$ of mass 2.5 kg moves on the table with a speed of $6 \text{ m s}^{-1}$ and collides directly with $B$. In the collision the two particles coalesce.
\begin{enumerate}[label=(\alph*)]
\item Find the speed of the combined particle after the collision. [2]
\item Find the loss of kinetic energy of the system due to the collision. [3]
\end{enumerate}
\hfill \mbox{\textit{CAIE M1 2020 Q1 [5]}}