The initial velocity of an object is $u = \begin{pmatrix} -5 \\ 3 \end{pmatrix} ms^{-1}$ . If the acceleration of the object is $a = \begin{pmatrix} 3 \\ -4 \end{pmatrix} ms^{-2}$ and it moved for 3 seconds, find the final velocity.

$\begin{pmatrix} -14 \\ 15 \end{pmatrix} ms^{-1}$

$\begin{pmatrix} -2 \\ 1 \end{pmatrix} ms^{-1}$

$\begin{pmatrix} 4 \\ -9 \end{pmatrix} ms^{-1}$

$\begin{pmatrix} 14 \\ -9 \end{pmatrix} ms^{-1}$

Correct answer is C

$u = \begin{pmatrix} -5 \\ 3 \end{pmatrix} ms^{-1}$

$a = \begin{pmatrix} 3 \\ -4 \end{pmatrix} ms^{-2}; t = 3 secs$

$v = u + at \implies v = \begin{pmatrix} -5 \\ 3 \end{pmatrix} + \begin{pmatrix} 3 \\ -4 \end{pmatrix} \times 3$

= $\begin{pmatrix} -5 \\ 3 \end{pmatrix} + \begin{pmatrix} 9 \\ -12 \end{pmatrix} = \begin{pmatrix} 4 \\ -9 \end{pmatrix} ms^{-1}$ \)

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The initial velocity of an object is u=(−53)ms−1u = \begin{pmatrix} -5 \\ 3 \end{pmatrix} ms^{-1}. If the acceleration of the object is a=(3−4)ms−2a = \begin{pmatrix} 3 \\ -4 \end{pmatrix} ms^{-2} and it moved for 3 seconds, find the final velocity.