Edexcel M2 2010 January — Question 1 8 marks

Exam BoardEdexcel
ModuleM2 (Mechanics 2)
Year2010
SessionJanuary
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeMaximum or minimum velocity
DifficultyStandard +0.3 This is a straightforward M2 calculus-based mechanics question requiring integration to find position, differentiation to find minimum velocity, then substitution. All steps are standard techniques with no novel insight required, making it slightly easier than average but still requiring multiple coordinated steps for 8 marks.
Spec1.07a Derivative as gradient: of tangent to curve1.07n Stationary points: find maxima, minima using derivatives1.08d Evaluate definite integrals: between limits3.02f Non-uniform acceleration: using differentiation and integration

A particle \(P\) moves along the \(x\)-axis. At time \(t\) seconds the velocity of \(P\) is \(v \text{ ms}^{-1}\) in the positive \(x\)-direction, where \(v = 3t^2 - 4t + 3\). When \(t = 0\), \(P\) is at the origin \(O\). Find the distance of \(P\) from \(O\) when \(P\) is moving with minimum velocity. [8]

AnswerMarks
\(\frac{dv}{dr} = 6t - 4\)M1 A1
\(6t - 4 = 0 \Rightarrow t = \frac{2}{3}\)M1 A1
\(s = \int 3t^2 - 4t + 3 \, dt = t^3 - 2t^2 + 3t (+c)\)M1 A1
\(t = \frac{2}{3} \Rightarrow s = -\frac{16}{27} + 2\) so distance is \(\frac{38}{27}\) mM1 A1
Total: [8]
$\frac{dv}{dr} = 6t - 4$ | M1 A1 |
$6t - 4 = 0 \Rightarrow t = \frac{2}{3}$ | M1 A1 |
$s = \int 3t^2 - 4t + 3 \, dt = t^3 - 2t^2 + 3t (+c)$ | M1 A1 |
$t = \frac{2}{3} \Rightarrow s = -\frac{16}{27} + 2$ so distance is $\frac{38}{27}$ m | M1 A1 |

**Total: [8]**

---
A particle $P$ moves along the $x$-axis. At time $t$ seconds the velocity of $P$ is $v \text{ ms}^{-1}$ in the positive $x$-direction, where $v = 3t^2 - 4t + 3$. When $t = 0$, $P$ is at the origin $O$. Find the distance of $P$ from $O$ when $P$ is moving with minimum velocity.
[8]

\hfill \mbox{\textit{Edexcel M2 2010 Q1 [8]}}