Edexcel M3 2004 January — Question 2 9 marks

Exam BoardEdexcel
ModuleM3 (Mechanics 3)
Year2004
SessionJanuary
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeDisplacement from velocity by integration
DifficultyModerate -0.3 This is a straightforward M3 variable acceleration question requiring two integrations with given initial conditions. The exponential function integrates cleanly, and finding instantaneous rest is a standard technique. While it requires calculus beyond C1-C2, it's a routine textbook exercise for M3 students with no novel problem-solving required.
Spec3.02f Non-uniform acceleration: using differentiation and integration3.02g Two-dimensional variable acceleration

2. A particle \(P\) moves along the \(x\)-axis. At time \(t\) seconds its acceleration is \(\left( - 4 \mathrm { e } ^ { - 2 t } \right) \mathrm { m } \mathrm { s } ^ { - 2 }\) in the direction of \(x\) increasing. When \(t = 0 , P\) is at the origin \(O\) and is moving with speed \(1 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) in the direction of \(x\) increasing.
  1. Find an expression for the velocity of \(P\) at time \(t\).
  2. Find the distance of \(P\) from \(O\) when \(P\) comes to instantaneous rest.
    (6)

2. A particle $P$ moves along the $x$-axis. At time $t$ seconds its acceleration is $\left( - 4 \mathrm { e } ^ { - 2 t } \right) \mathrm { m } \mathrm { s } ^ { - 2 }$ in the direction of $x$ increasing. When $t = 0 , P$ is at the origin $O$ and is moving with speed $1 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ in the direction of $x$ increasing.
\begin{enumerate}[label=(\alph*)]
\item Find an expression for the velocity of $P$ at time $t$.
\item Find the distance of $P$ from $O$ when $P$ comes to instantaneous rest.\\
(6)
\end{enumerate}

\hfill \mbox{\textit{Edexcel M3 2004 Q2 [9]}}