Edexcel M1 2003 June — Question 5 10 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2003
SessionJune
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicConstant acceleration (SUVAT)
TypeConstant acceleration vector (i and j)
DifficultyModerate -0.3 This is a straightforward vector kinematics question requiring standard application of v = u + at in component form. Part (a) requires setting the j-component to zero, part (b) needs magnitude calculation, and part (c) involves basic trigonometry. All steps are routine M1 techniques with no problem-solving insight required, making it slightly easier than average.
Spec1.10a Vectors in 2D: i,j notation and column vectors1.10c Magnitude and direction: of vectors1.10h Vectors in kinematics: uniform acceleration in vector form

5. A particle \(P\) moves with constant acceleration \(( 2 \mathbf { i } - 3 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }\). At time \(t\) seconds, its velocity is \(\mathbf { v } \mathrm { m } \mathrm { s } ^ { - 1 }\). When \(t = 0 , \mathbf { v } = - 2 \mathbf { i } + 7 \mathbf { j }\).
  1. Find the value of \(t\) when \(P\) is moving parallel to the vector \(\mathbf { i }\).
  2. Find the speed of \(P\) when \(t = 3\).
  3. Find the angle between the vector \(\mathbf { j }\) and the direction of motion of \(P\) when \(t = 3\).

Question 5:
Part (a):
AnswerMarks Guidance
WorkingMarks Notes
\(v = u + at\): \(\mathbf{v} = (-2+2t)\mathbf{i} + (7-3t)\mathbf{j}\)M1 A1
\(\mathbf{v}\) parallel to \(\mathbf{i} \Rightarrow 7-3t=0 \Rightarrow t=2\frac{1}{3}\) sM1 A1 (4)
Part (b):
AnswerMarks Guidance
WorkingMarks Notes
\(t=3\), \(\mathbf{v} = 4\mathbf{i} - 2\mathbf{j}\)M1
\(\mathbf{v} = \sqrt{20} \approx 4.47\) m s\(^{-1}\)
Part (c):
AnswerMarks Guidance
WorkingMarks Notes
Angle \(= (\arctan\frac{2}{4}) + 90° = 116.6°\)M1, M1 A1 accept 117°
\([\text{or } 180° - (\arctan\frac{4}{2})]\)[M1 M1 A1] (3)
# Question 5:

## Part (a):
| Working | Marks | Notes |
|---------|-------|-------|
| $v = u + at$: $\mathbf{v} = (-2+2t)\mathbf{i} + (7-3t)\mathbf{j}$ | M1 A1 | |
| $\mathbf{v}$ parallel to $\mathbf{i} \Rightarrow 7-3t=0 \Rightarrow t=2\frac{1}{3}$ s | M1 A1 | (4) |

## Part (b):
| Working | Marks | Notes |
|---------|-------|-------|
| $t=3$, $\mathbf{v} = 4\mathbf{i} - 2\mathbf{j}$ | M1 | |
| $|\mathbf{v}| = \sqrt{20} \approx 4.47$ m s$^{-1}$ | M1 A1 | (3) |

## Part (c):
| Working | Marks | Notes |
|---------|-------|-------|
| Angle $= (\arctan\frac{2}{4}) + 90° = 116.6°$ | M1, M1 A1 | accept 117° |
| $[\text{or } 180° - (\arctan\frac{4}{2})]$ | [M1 M1 A1] | (3) |

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5. A particle $P$ moves with constant acceleration $( 2 \mathbf { i } - 3 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 2 }$. At time $t$ seconds, its velocity is $\mathbf { v } \mathrm { m } \mathrm { s } ^ { - 1 }$. When $t = 0 , \mathbf { v } = - 2 \mathbf { i } + 7 \mathbf { j }$.
\begin{enumerate}[label=(\alph*)]
\item Find the value of $t$ when $P$ is moving parallel to the vector $\mathbf { i }$.
\item Find the speed of $P$ when $t = 3$.
\item Find the angle between the vector $\mathbf { j }$ and the direction of motion of $P$ when $t = 3$.
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2003 Q5 [10]}}