Edexcel M1 2018 January — Question 3 7 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2018
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMomentum and Collisions
TypeCollision with two possible outcomes
DifficultyStandard +0.3 This is a straightforward M1 collision problem requiring standard application of impulse-momentum and conservation of momentum. Part (a) is direct calculation of impulse from change in momentum. Part (b) requires setting up momentum conservation and solving an inequality, but the algebra is routine with no conceptual surprises. Slightly easier than average due to clear setup and standard techniques.
Spec6.03a Linear momentum: p = mv6.03b Conservation of momentum: 1D two particles6.03e Impulse: by a force6.03f Impulse-momentum: relation

3. Two particles \(A\) and \(B\) have mass \(2 m\) and \(k m\) respectively. The particles are moving in opposite directions along the same straight smooth horizontal line so that the particles collide directly. Immediately before the collision \(A\) has speed \(2 u\) and \(B\) has speed \(u\). The direction of motion of each particle is reversed by the collision. Immediately after the collision the speed of \(A\) is \(\frac { u } { 2 }\).
  1. Find, in terms of \(m\) and \(u\), the magnitude of the impulse exerted by \(B\) on \(A\) in the collision.
  2. Show that \(k < 5\)

3. Two particles $A$ and $B$ have mass $2 m$ and $k m$ respectively. The particles are moving in opposite directions along the same straight smooth horizontal line so that the particles collide directly. Immediately before the collision $A$ has speed $2 u$ and $B$ has speed $u$. The direction of motion of each particle is reversed by the collision. Immediately after the collision the speed of $A$ is $\frac { u } { 2 }$.
\begin{enumerate}[label=(\alph*)]
\item Find, in terms of $m$ and $u$, the magnitude of the impulse exerted by $B$ on $A$ in the collision.
\item Show that $k < 5$

\begin{center}

\end{center}
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2018 Q3 [7]}}