OCR H240/03 2017 Specimen — Question 12 14 marks

Exam BoardOCR
ModuleH240/03 (Pure Mathematics and Mechanics)
Year2017
SessionSpecimen
Marks14
TopicProjectiles
TypeProjectile clearing obstacle
DifficultyStandard +0.3 This is a standard projectile motion question requiring routine application of SUVAT equations and trajectory formulas. Part (a) involves finding maximum height and vertical position at a given horizontal distance—both textbook exercises. Part (b) requires solving a quadratic equation from the trajectory equation. Parts (c) and (d) are standard modelling commentary. The calculations are straightforward with no novel problem-solving required, making this slightly easier than average.
Spec3.02h Motion under gravity: vector form3.02i Projectile motion: constant acceleration model

A girl is practising netball. She throws the ball from a height of 1.5 m above horizontal ground and aims to get the ball through a hoop. The hoop is 2.5 m vertically above the ground and is 6 m horizontally from the point of projection. The situation is modelled as follows.
  • The initial velocity of the ball has magnitude \(U\) m s\(^{-1}\).
  • The angle of projection is \(40°\).
  • The ball is modelled as a particle.
  • The hoop is modelled as a point.
This is shown on the diagram below. \includegraphics{figure_12}
  1. For \(U = 10\), find
    1. the greatest height above the ground reached by the ball [5]
    2. the distance between the ball and the hoop when the ball is vertically above the hoop. [4]
  2. Calculate the value of \(U\) which allows her to hit the hoop. [3]
  3. How appropriate is this model for predicting the path of the ball when it is thrown by the girl? [1]
  4. Suggest one improvement that might be made to this model. [1]

A girl is practising netball. She throws the ball from a height of 1.5 m above horizontal ground and aims to get the ball through a hoop. The hoop is 2.5 m vertically above the ground and is 6 m horizontally from the point of projection.

The situation is modelled as follows.
\begin{itemize}
\item The initial velocity of the ball has magnitude $U$ m s$^{-1}$.
\item The angle of projection is $40°$.
\item The ball is modelled as a particle.
\item The hoop is modelled as a point.
\end{itemize}

This is shown on the diagram below.

\includegraphics{figure_12}

\begin{enumerate}[label=(\alph*)]
\item For $U = 10$, find
\begin{enumerate}[label=(\roman*)]
\item the greatest height above the ground reached by the ball [5]
\item the distance between the ball and the hoop when the ball is vertically above the hoop. [4]
\end{enumerate}

\item Calculate the value of $U$ which allows her to hit the hoop. [3]

\item How appropriate is this model for predicting the path of the ball when it is thrown by the girl? [1]

\item Suggest one improvement that might be made to this model. [1]
\end{enumerate}

\hfill \mbox{\textit{OCR H240/03 2017 Q12 [14]}}