WJEC Unit 4 2018 June — Question 9 10 marks

Exam BoardWJEC
ModuleUnit 4 (Unit 4)
Year2018
SessionJune
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProjectiles
TypeTwo projectiles meeting - 2D flight
DifficultyStandard +0.8 Part (a) is a standard projectile range calculation using R = (u²sin2α)/g. Part (b) requires setting up simultaneous equations for two projectiles moving towards each other with a time delay, then solving for collision position and height—this involves more sophisticated problem-solving and algebraic manipulation than typical projectile questions, elevating it above average difficulty.
Spec3.02h Motion under gravity: vector form3.02i Projectile motion: constant acceleration model

Points \(A\) and \(B\) lie on horizontal ground. At time \(t = 0\) seconds, an object \(P\) is projected from \(A\) towards \(B\) such that \(AB\) is the range of \(P\). The speed of projection is \(24 \cdot 5\) ms\(^{-1}\) in a direction which is 30° above the horizontal.
  1. Calculate the range \(AB\) of the object \(P\). [5]
At time \(t = 1\) second, another object \(Q\) is projected from \(B\) towards \(A\) with the same speed of projection \(24 \cdot 5\) ms\(^{-1}\) and in a direction which is also 30° above the horizontal.
  1. Determine the height above the ground at which \(P\) and \(Q\) collide. [5]

Points $A$ and $B$ lie on horizontal ground. At time $t = 0$ seconds, an object $P$ is projected from $A$ towards $B$ such that $AB$ is the range of $P$. The speed of projection is $24 \cdot 5$ ms$^{-1}$ in a direction which is 30° above the horizontal.

\begin{enumerate}[label=(\alph*)]
\item Calculate the range $AB$ of the object $P$. [5]
\end{enumerate}

At time $t = 1$ second, another object $Q$ is projected from $B$ towards $A$ with the same speed of projection $24 \cdot 5$ ms$^{-1}$ and in a direction which is also 30° above the horizontal.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Determine the height above the ground at which $P$ and $Q$ collide. [5]
\end{enumerate}

\hfill \mbox{\textit{WJEC Unit 4 2018 Q9 [10]}}