| Exam Board | Edexcel |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2016 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Momentum and Collisions |
| Type | Direct collision, find mass |
| Difficulty | Moderate -0.3 This is a straightforward momentum conservation problem with clearly defined before/after states. Part (a) requires setting up and solving a single equation using conservation of momentum with given velocities. Part (b) is a direct application of the impulse-momentum theorem. The algebraic manipulation is minimal and the problem follows a standard textbook template for M1 collision questions, making it slightly easier than average. |
| Spec | 6.03a Linear momentum: p = mv6.03b Conservation of momentum: 1D two particles6.03e Impulse: by a force6.03f Impulse-momentum: relation |
Two particles $P$ and $Q$ are moving in opposite directions along the same horizontal straight line. Particle $P$ has mass $m$ and particle $Q$ has mass $km$. The particles collide directly. Immediately before the collision, the speed of $P$ is $u$ and the speed of $Q$ is $2u$. As a result of the collision, the direction of motion of each particle is reversed and the speed of each particle is halved.
\begin{enumerate}[label=(\alph*)]
\item Find the value of $k$.
[4]
\item Find, in terms of $m$ and $u$ only, the magnitude of the impulse exerted on $Q$ by $P$ in the collision.
[2]
\end{enumerate}
\hfill \mbox{\textit{Edexcel M1 2016 Q2 [6]}}