AQA M1 2010 January — Question 5 14 marks

Exam BoardAQA
ModuleM1 (Mechanics 1)
Year2010
SessionJanuary
Marks14
PaperDownload PDF ↗
TopicForces, equilibrium and resultants
TypeForces in vector form: kinematics extension
DifficultyModerate -0.8 This is a straightforward M1 vector mechanics question requiring only routine procedures: vector addition, applying F=ma, using constant acceleration equations (v=u+at), and solving a simple quadratic. All steps are standard textbook exercises with no problem-solving insight needed, making it easier than average.
Spec1.10d Vector operations: addition and scalar multiplication3.02f Non-uniform acceleration: using differentiation and integration3.02g Two-dimensional variable acceleration3.03a Force: vector nature and diagrams3.03c Newton's second law: F=ma one dimension3.03d Newton's second law: 2D vectors

5 The constant forces \(\mathbf { F } _ { 1 } = ( 8 \mathbf { i } + 12 \mathbf { j } )\) newtons and \(\mathbf { F } _ { 2 } = ( 4 \mathbf { i } - 4 \mathbf { j } )\) newtons act on a particle. No other forces act on the particle.
  1. Find the resultant force acting on the particle.
  2. Given that the mass of the particle is 4 kg , show that the acceleration of the particle is \(( 3 \mathbf { i } + 2 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }\).
  3. At time \(t\) seconds, the velocity of the particle is \(\mathbf { v } \mathrm { m } \mathrm { s } ^ { - 1 }\).
    1. When \(t = 20 , \mathbf { v } = 40 \mathbf { i } + 32 \mathbf { j }\). Show that \(\mathbf { v } = - 20 \mathbf { i } - 8 \mathbf { j }\) when \(t = 0\).
    2. Write down an expression for \(\mathbf { v }\) at time \(t\).
    3. Find the times when the speed of the particle is \(8 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).

5 The constant forces $\mathbf { F } _ { 1 } = ( 8 \mathbf { i } + 12 \mathbf { j } )$ newtons and $\mathbf { F } _ { 2 } = ( 4 \mathbf { i } - 4 \mathbf { j } )$ newtons act on a particle. No other forces act on the particle.
\begin{enumerate}[label=(\alph*)]
\item Find the resultant force acting on the particle.
\item Given that the mass of the particle is 4 kg , show that the acceleration of the particle is $( 3 \mathbf { i } + 2 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }$.
\item At time $t$ seconds, the velocity of the particle is $\mathbf { v } \mathrm { m } \mathrm { s } ^ { - 1 }$.
\begin{enumerate}[label=(\roman*)]
\item When $t = 20 , \mathbf { v } = 40 \mathbf { i } + 32 \mathbf { j }$.

Show that $\mathbf { v } = - 20 \mathbf { i } - 8 \mathbf { j }$ when $t = 0$.
\item Write down an expression for $\mathbf { v }$ at time $t$.
\item Find the times when the speed of the particle is $8 \mathrm {~m} \mathrm {~s} ^ { - 1 }$.
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{AQA M1 2010 Q5 [14]}}