Edexcel M2 Specimen — Question 5 9 marks

Exam BoardEdexcel
ModuleM2 (Mechanics 2)
SessionSpecimen
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicImpulse and momentum (advanced)
TypeImpulse from velocity change
DifficultyModerate -0.3 This is a straightforward M2 mechanics question requiring standard application of impulse-momentum theorem (impulse = change in momentum) and kinetic energy formula. All three parts involve direct substitution into formulas with vector arithmetic—no problem-solving insight or novel approach needed, though the vector components and multi-part structure make it slightly more involved than the most basic recall questions.
Spec6.02d Mechanical energy: KE and PE concepts6.03a Linear momentum: p = mv6.03e Impulse: by a force6.03f Impulse-momentum: relation

5. [In this question \(\mathbf { i }\) and \(\mathbf { j }\) are perpendi cular unit vectors in a horizontal plane.] A ball of mass 0.5 kg is moving with velocity \(( 10 \mathbf { i } + 24 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 1 }\) when it is struck by a bat. Immediately after the impact the ball is moving with velocity \(20 \mathbf { i } \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Find
  1. the magnitude of the impulse of the bat on the ball,
  2. the size of the angle between the vector \(\mathbf { i }\) and the impulse exerted by the bat on the ball,
  3. the kinetic energy lost by the ball in the impact.

Question 5:
Part (a):
AnswerMarks Guidance
WorkingMarks Notes
\(\mathbf{I} = m\mathbf{v} - m\mathbf{u}\)M1
\(= 0.5 \times 20\mathbf{i} - 0.5(10\mathbf{i} + 24\mathbf{j})\)A1
\(= 5\mathbf{i} - 12\mathbf{j}\)
\(5\mathbf{i} - 12\mathbf{j} = 13\) Ns
Part (b):
AnswerMarks Guidance
WorkingMarks Notes
\(\tan\theta = \frac{12}{5}\)M1
\(\theta = 67.4°\)A1 (2 marks)
Part (c):
AnswerMarks Guidance
WorkingMarks Notes
K.E. lost \(= \frac{1}{2} \times 0.5(10^2 + 24^2) - \frac{1}{2} \times 0.5 \times 20^2\)M1 A1
\(= 69\) JA1 (3 marks)
# Question 5:

## Part (a):
| Working | Marks | Notes |
|---------|-------|-------|
| $\mathbf{I} = m\mathbf{v} - m\mathbf{u}$ | M1 | |
| $= 0.5 \times 20\mathbf{i} - 0.5(10\mathbf{i} + 24\mathbf{j})$ | A1 | |
| $= 5\mathbf{i} - 12\mathbf{j}$ | | |
| $|5\mathbf{i} - 12\mathbf{j}| = 13$ Ns | M1 A1 | (4 marks) |

## Part (b):
| Working | Marks | Notes |
|---------|-------|-------|
| $\tan\theta = \frac{12}{5}$ | M1 | |
| $\theta = 67.4°$ | A1 | (2 marks) |

## Part (c):
| Working | Marks | Notes |
|---------|-------|-------|
| K.E. lost $= \frac{1}{2} \times 0.5(10^2 + 24^2) - \frac{1}{2} \times 0.5 \times 20^2$ | M1 A1 | |
| $= 69$ J | A1 | (3 marks) |

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5. [In this question $\mathbf { i }$ and $\mathbf { j }$ are perpendi cular unit vectors in a horizontal plane.]

A ball of mass 0.5 kg is moving with velocity $( 10 \mathbf { i } + 24 \mathbf { j } ) \mathrm { m } \mathrm { s } ^ { - 1 }$ when it is struck by a bat. Immediately after the impact the ball is moving with velocity $20 \mathbf { i } \mathrm {~m} \mathrm {~s} ^ { - 1 }$.

Find
\begin{enumerate}[label=(\alph*)]
\item the magnitude of the impulse of the bat on the ball,
\item the size of the angle between the vector $\mathbf { i }$ and the impulse exerted by the bat on the ball,
\item the kinetic energy lost by the ball in the impact.
\end{enumerate}

\hfill \mbox{\textit{Edexcel M2  Q5 [9]}}