OCR MEI AS Paper 1 Specimen — Question 5 5 marks

Exam BoardOCR MEI
ModuleAS Paper 1 (AS Paper 1)
SessionSpecimen
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeFinding when particle at rest
DifficultyModerate -0.8 This is a straightforward kinematics question requiring differentiation of a cubic to find velocity, solving a quadratic equation, then substituting back. All steps are routine calculus applications with no problem-solving insight needed, making it easier than average but not trivial due to the algebraic manipulation required.
Spec1.07i Differentiate x^n: for rational n and sums3.02a Kinematics language: position, displacement, velocity, acceleration

5 Particle P moves on a straight line that contains the point O .
At time \(t\) seconds the displacement of P from O is \(s\) metres, where \(s = t ^ { 3 } - 3 t ^ { 2 } + 3\).
  1. Determine the times when the particle has zero velocity.
  2. Find the distances of P from O at the times when it has zero velocity.

Question 5:
Part (a):
AnswerMarks Guidance
AnswerMarks Guidance
Velocity \(v\) is \(\frac{ds}{dt} = 3t^2 - 6t\)M1 Attempt to find \(\frac{ds}{dt}\)
\(= 0\)M1 \(\frac{ds}{dt} = 0\) must be stated
\(t = 0\) or \(2\)A1 Both roots found
Part (b):
AnswerMarks Guidance
AnswerMarks Guidance
\(s(0) = 3\) so distance \(3\) mA1 Accept seeing 3 without comment
\(s(2) = 8 - 12 + 3 = -1\) so distance is \(1\) mA1 \(-1\) for \(s\) must be seen as well as \(1\) m for distance
# Question 5:

## Part (a):
| Answer | Marks | Guidance |
|--------|-------|----------|
| Velocity $v$ is $\frac{ds}{dt} = 3t^2 - 6t$ | M1 | Attempt to find $\frac{ds}{dt}$ |
| $= 0$ | M1 | $\frac{ds}{dt} = 0$ must be stated |
| $t = 0$ or $2$ | A1 | Both roots found |

## Part (b):
| Answer | Marks | Guidance |
|--------|-------|----------|
| $s(0) = 3$ so distance $3$ m | A1 | Accept seeing 3 without comment |
| $s(2) = 8 - 12 + 3 = -1$ so distance is $1$ m | A1 | $-1$ for $s$ must be seen as well as $1$ m for distance |

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5 Particle P moves on a straight line that contains the point O .\\
At time $t$ seconds the displacement of P from O is $s$ metres, where $s = t ^ { 3 } - 3 t ^ { 2 } + 3$.
\begin{enumerate}[label=(\alph*)]
\item Determine the times when the particle has zero velocity.
\item Find the distances of P from O at the times when it has zero velocity.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI AS Paper 1  Q5 [5]}}