Edexcel M1 2012 January — Question 1 5 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2012
SessionJanuary
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMomentum and Collisions
TypeDirect collision, find impulse magnitude
DifficultyModerate -0.8 This is a straightforward M1 momentum question requiring direct application of conservation of momentum and impulse = change in momentum. The setup is clear, all values are given, and it involves standard two-step calculations with no conceptual subtlety or problem-solving insight required.
Spec6.03b Conservation of momentum: 1D two particles6.03f Impulse-momentum: relation

  1. A railway truck \(P\), of mass \(m \mathrm {~kg}\), is moving along a straight horizontal track with speed \(15 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Truck \(P\) collides with a truck \(Q\) of mass 3000 kg , which is at rest on the same track. Immediately after the collision the speed of \(P\) is \(3 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and the speed of \(Q\) is \(9 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The direction of motion of \(P\) is reversed by the collision.
Modelling the trucks as particles, find
  1. the magnitude of the impulse exerted by \(P\) on \(Q\),
  2. the value of \(m\).

\begin{enumerate}
  \item A railway truck $P$, of mass $m \mathrm {~kg}$, is moving along a straight horizontal track with speed $15 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. Truck $P$ collides with a truck $Q$ of mass 3000 kg , which is at rest on the same track. Immediately after the collision the speed of $P$ is $3 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ and the speed of $Q$ is $9 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. The direction of motion of $P$ is reversed by the collision.
\end{enumerate}

Modelling the trucks as particles, find\\
(a) the magnitude of the impulse exerted by $P$ on $Q$,\\
(b) the value of $m$.\\

\hfill \mbox{\textit{Edexcel M1 2012 Q1 [5]}}