CAIE M2 2013 November — Question 7

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2013
SessionNovember
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors Introduction & 2D
TypeRelative velocity: find resultant velocity (magnitude and/or direction)
DifficultyModerate -0.5 The question text appears corrupted/incomplete, but based on the topic (Vectors Introduction & 2D) and module (M2 Mechanics), this likely involves basic 2D vector operations with velocities. Standard M2 vector questions involving velocity vectors are typically straightforward applications of vector addition/subtraction and basic mechanics, making them slightly easier than average A-level questions.

\(A\) has velocity \(\vec{x}\)
    1. \(C\)
  1. \(A\) has velocity \(\vec{x}\)
    1. \(C\)
  2. \(C\) with velocities \(v \vec{v}\)

(i)
AnswerMarks Guidance
\(0.4gd = 32(d-0.8)^2/(2 \times 0.8)\)M1 PE/EE balance
\(20d^2 - 36d + 12.8 = 0\)M1 Solves 3 term quadratic
\(d = 1.31 \text{ m only}\)A1 [4]
OR
AnswerMarks Guidance
\(0.4g(0.8 + e) = 32e^2/(2 \times 0.8)\)M1 PE/EE balance
\(20e^2 - 4e + 3.2 = 0\)A1
\(e = 0.5(1)\) (also \(-3.12\))M1 Solves 3 term quadratic
\(d = 1.31 \text{ m only}\)A1
(ii)
AnswerMarks Guidance
\(0.4v^2/2\)A1
\(= 0.4g \times 1 - 32(1-0.8)^2/(2 \times 0.8)\)
\(v = 4 \text{ ms}^{-1}\)A1 [3]
(iii)
AnswerMarks Guidance
Rebound \(v = 0.8\)B1ft \(\text{flcv}(v(\text{ii}) = \sqrt{(1-0.96)} = 0.2v(\text{ii})\)
\(0 = 0.4 \times 0.8^2/2 + 32 \times 0.2^2/1.6 - 0.4gh\)M1 EE/PE/KE balance, \(h = 0.232\)
\(OP (=1-h) = 0.768 \text{ m}\)A1 [3]
**(i)**

$0.4gd = 32(d-0.8)^2/(2 \times 0.8)$ | M1 | PE/EE balance
$20d^2 - 36d + 12.8 = 0$ | M1 | Solves 3 term quadratic
$d = 1.31 \text{ m only}$ | A1 | [4] | Other value $0.4876..$

**OR**

$0.4g(0.8 + e) = 32e^2/(2 \times 0.8)$ | M1 | PE/EE balance
$20e^2 - 4e + 3.2 = 0$ | A1 |
$e = 0.5(1)$ (also $-3.12$) | M1 | Solves 3 term quadratic
$d = 1.31 \text{ m only}$ | A1 |

**(ii)**

$0.4v^2/2$ | A1 |
$= 0.4g \times 1 - 32(1-0.8)^2/(2 \times 0.8)$ | |
$v = 4 \text{ ms}^{-1}$ | A1 | [3]

**(iii)**

Rebound $v = 0.8$ | B1ft | $\text{flcv}(v(\text{ii}) = \sqrt{(1-0.96)} = 0.2v(\text{ii})$
$0 = 0.4 \times 0.8^2/2 + 32 \times 0.2^2/1.6 - 0.4gh$ | M1 | EE/PE/KE balance, $h = 0.232$
$OP (=1-h) = 0.768 \text{ m}$ | A1 | [3] | [10]
$A$ has velocity $\vec{x}$

\begin{enumerate}[label=(\alph*)]
\item 
\begin{enumerate}[label=(\roman*)]
\item $C$
\end{enumerate}
\item $A$ has velocity $\vec{x}$
\begin{enumerate}[label=(\roman*)]
\item $C$
\end{enumerate}
\item $C$ with velocities $v \vec{v}$
\end{enumerate}

\hfill \mbox{\textit{CAIE M2 2013 Q7}}