AQA M1 2012 January — Question 7 12 marks

Exam BoardAQA
ModuleM1 (Mechanics 1)
Year2012
SessionJanuary
Marks12
PaperDownload PDF ↗
TopicSUVAT in 2D & Gravity
TypeParticle motion: 2D constant acceleration
DifficultyStandard +0.3 This is a straightforward 2D SUVAT question requiring standard application of kinematic equations with constant acceleration. Parts (a) and (b) are direct substitution into s=ut+½at² and v=u+at. Part (c) requires finding when vertical displacement equals 180m, then calculating speed from velocity components—routine problem-solving for M1 with no conceptual challenges beyond basic vector mechanics.
Spec1.10a Vectors in 2D: i,j notation and column vectors1.10c Magnitude and direction: of vectors3.02e Two-dimensional constant acceleration: with vectors3.02g Two-dimensional variable acceleration

7 A helicopter is initially at rest on the ground at the origin when it begins to accelerate in a vertical plane. Its acceleration is \(( 4.2 \mathbf { i } + 2.5 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }\) for the first 20 seconds of its motion. The unit vectors \(\mathbf { i }\) and \(\mathbf { j }\) are horizontal and vertical respectively. Assume that the helicopter moves over horizontal ground.
  1. Find the height of the helicopter above the ground at the end of the 20 seconds.
  2. Find the velocity of the helicopter at the end of the 20 seconds.
  3. Find the speed of the helicopter when it is at a height of 180 metres above the ground.

7 A helicopter is initially at rest on the ground at the origin when it begins to accelerate in a vertical plane. Its acceleration is $( 4.2 \mathbf { i } + 2.5 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }$ for the first 20 seconds of its motion. The unit vectors $\mathbf { i }$ and $\mathbf { j }$ are horizontal and vertical respectively.

Assume that the helicopter moves over horizontal ground.
\begin{enumerate}[label=(\alph*)]
\item Find the height of the helicopter above the ground at the end of the 20 seconds.
\item Find the velocity of the helicopter at the end of the 20 seconds.
\item Find the speed of the helicopter when it is at a height of 180 metres above the ground.
\end{enumerate}

\hfill \mbox{\textit{AQA M1 2012 Q7 [12]}}