Edexcel M2 2013 June — Question 3 13 marks

Exam BoardEdexcel
ModuleM2 (Mechanics 2)
Year2013
SessionJune
Marks13
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeTotal distance with direction changes
DifficultyModerate -0.8 This is a straightforward M2 kinematics question requiring only standard techniques: factorizing a quadratic to find when v=0, evaluating v at critical points and endpoints for maximum speed, and integrating |v| between rest points for distance. All steps are routine with no problem-solving insight needed, making it easier than average but not trivial due to the multi-part nature and need for careful sign consideration.
Spec1.02f Solve quadratic equations: including in a function of unknown3.02a Kinematics language: position, displacement, velocity, acceleration3.02c Interpret kinematic graphs: gradient and area

3. A particle \(P\) moves on the \(x\)-axis. At time \(t\) seconds the velocity of \(P\) is \(v \mathrm {~m} \mathrm {~s} ^ { - 1 }\) in the direction of \(x\) increasing, where $$v = 2 t ^ { 2 } - 14 t + 20 , \quad t \geqslant 0$$ Find
  1. the times when \(P\) is instantaneously at rest,
  2. the greatest speed of \(P\) in the interval \(0 \leqslant t \leqslant 4\)
  3. the total distance travelled by \(P\) in the interval \(0 \leqslant t \leqslant 4\)

3. A particle $P$ moves on the $x$-axis. At time $t$ seconds the velocity of $P$ is $v \mathrm {~m} \mathrm {~s} ^ { - 1 }$ in the direction of $x$ increasing, where

$$v = 2 t ^ { 2 } - 14 t + 20 , \quad t \geqslant 0$$

Find
\begin{enumerate}[label=(\alph*)]
\item the times when $P$ is instantaneously at rest,
\item the greatest speed of $P$ in the interval $0 \leqslant t \leqslant 4$
\item the total distance travelled by $P$ in the interval $0 \leqslant t \leqslant 4$
\end{enumerate}

\hfill \mbox{\textit{Edexcel M2 2013 Q3 [13]}}