OCR AS Pure 2017 Specimen — Question 10 10 marks

Exam BoardOCR
ModuleAS Pure (AS Pure Mathematics)
Year2017
SessionSpecimen
Marks10
TopicApplied differentiation
TypeKinematics: displacement-velocity-acceleration
DifficultyModerate -0.3 This is a straightforward calculus application question requiring routine differentiation and finding stationary points. All parts follow standard procedures (substitution, differentiation for velocity/acceleration, solving quadratic for maximum), making it slightly easier than average despite being multi-part with 10 marks total.
Spec1.07i Differentiate x^n: for rational n and sums3.02f Non-uniform acceleration: using differentiation and integration

A student is attempting to model the flight of a boomerang. She throws the boomerang from a fixed point \(O\) and catches it when it returns to \(O\). She suggests the model for the displacement, \(s\) metres, after \(t\) seconds is given by \(s = 9t^2 - \frac{3}{2}t^3\), \(0 \leq t \leq 6\). For this model,
  1. determine what happens at \(t = 6\), [2]
  2. find the greatest displacement of the boomerang from \(O\), [4]
  3. find the velocity of the boomerang 1 second before the student catches it, [2]
  4. find the acceleration of the boomerang 1 second before the student catches it. [2]

A student is attempting to model the flight of a boomerang.
She throws the boomerang from a fixed point $O$ and catches it when it returns to $O$.

She suggests the model for the displacement, $s$ metres, after $t$ seconds is given by

$s = 9t^2 - \frac{3}{2}t^3$, $0 \leq t \leq 6$.

For this model,

\begin{enumerate}[label=(\alph*)]
\item determine what happens at $t = 6$, [2]

\item find the greatest displacement of the boomerang from $O$, [4]

\item find the velocity of the boomerang 1 second before the student catches it, [2]

\item find the acceleration of the boomerang 1 second before the student catches it. [2]
\end{enumerate}

\hfill \mbox{\textit{OCR AS Pure 2017 Q10 [10]}}