| Exam Board | Edexcel |
|---|---|
| Module | M2 (Mechanics 2) |
| Year | 2016 |
| Session | June |
| Marks | 12 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions 1 |
| Type | Collision followed by wall impact |
| Difficulty | Standard +0.3 This is a standard M2 collision problem with straightforward application of conservation of momentum and Newton's restitution law, followed by impulse calculation and a simple comparison of velocities. All steps are routine textbook exercises requiring no novel insight, making it slightly easier than average for M2 level. |
| Spec | 6.03b Conservation of momentum: 1D two particles6.03e Impulse: by a force6.03f Impulse-momentum: relation6.03i Coefficient of restitution: e6.03j Perfectly elastic/inelastic: collisions6.03k Newton's experimental law: direct impact |
7. Two particles $A$ and $B$, of mass $2 m$ and $3 m$ respectively, are initially at rest on a smooth horizontal surface. Particle $A$ is projected with speed $3 u$ towards $B$. Particle $A$ collides directly with particle $B$. The coefficient of restitution between $A$ and $B$ is $\frac { 3 } { 4 }$
\begin{enumerate}[label=(\alph*)]
\item Find
\begin{enumerate}[label=(\roman*)]
\item the speed of $A$ immediately after the collision,
\item the speed of $B$ immediately after the collision.
After the collision $B$ hits a fixed smooth vertical wall and rebounds. The wall is perpendicular to the direction of motion of $B$. The coefficient of restitution between $B$ and the wall is $e$. The magnitude of the impulse received by $B$ when it hits the wall is $\frac { 27 } { 4 } m u$.
\end{enumerate}\item Find the value of $e$.
\item Determine whether there is a further collision between $A$ and $B$ after $B$ rebounds from the wall.\\
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\end{enumerate}
\hfill \mbox{\textit{Edexcel M2 2016 Q7 [12]}}