| Exam Board | OCR |
|---|---|
| Module | M2 (Mechanics 2) |
| Year | 2012 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions 1 |
| Type | Particle-wall perpendicular collision |
| Difficulty | Moderate -0.8 This is a straightforward application of standard mechanics formulas (impulse = m(v-u) and coefficient of restitution e = speed after/speed before) with simple arithmetic. It requires only direct recall and substitution into well-practiced formulas with no problem-solving insight or multi-step reasoning beyond basic calculation. |
| Spec | 6.03f Impulse-momentum: relation |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| Speed \(= 1.2 \text{ ms}^{-1}\) | B1 | May be seen anywhere, even in (ii); allow \(-1.2\) |
| Impulse \(= 0.8 \times \pm(4 - -1.2)\) | M1 | Difference between momenta, allow \(0.8 \times \pm(4-1.2)\) |
| \(\pm 4.16\) Ns | A1 | |
| [3] |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| KE lost \(= \frac{1}{2} \times 0.8 \times (4^2 - (\pm 1.2)^2)\) | M1 | |
| \(5.82(4)\) J | A1 | Allow \(-5.82(4)\) |
| [2] |
## Question 1:
### Part (i):
| Answer | Marks | Guidance |
|--------|-------|----------|
| Speed $= 1.2 \text{ ms}^{-1}$ | B1 | May be seen anywhere, even in (ii); allow $-1.2$ |
| Impulse $= 0.8 \times \pm(4 - -1.2)$ | M1 | Difference between momenta, allow $0.8 \times \pm(4-1.2)$ |
| $\pm 4.16$ Ns | A1 | |
| **[3]** | | |
### Part (ii):
| Answer | Marks | Guidance |
|--------|-------|----------|
| KE lost $= \frac{1}{2} \times 0.8 \times (4^2 - (\pm 1.2)^2)$ | M1 | |
| $5.82(4)$ J | A1 | Allow $-5.82(4)$ |
| **[2]** | | |
---1 A particle, of mass 0.8 kg , moves along a smooth horizontal surface. It hits a vertical wall, which is at right angles to the direction of motion of the particle, and rebounds. The speed of the particle as it hits the wall is $4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ and the coefficient of restitution between the particle and the wall is 0.3 . Find\\
(i) the impulse that the wall exerts on the particle,\\
(ii) the kinetic energy lost in the impact.
\hfill \mbox{\textit{OCR M2 2012 Q1 [5]}}