Question $3(4$ points$)$

The rectangular coordinates of a particle which moves with curvilinear motion are given by $x=10\mathrm{.}25t+$

$1\mathrm{.}75t2-0\mathrm{.}45t3$ and $y=6\mathrm{.}32+14\mathrm{.}65t-2\mathrm{.}48t2,$ where x and y are in millimetres and the time t is in seconds,

beginning from $t=0.$ Determine the acceleration $a$ of the particle when $t=4\mathrm{.}62s.$ Give your answer in $m\frac{m}{?}$

$s^2.$