Answer
$3.64m/s^{2}$
Work Step by Step
$t=\frac{110}{2\times25cos20^{\circ}}$
Again, $v=u+at$
$0=25sin20^{\circ}-at$
$a=\frac{25sin20^{\circ}}{t}$
$a=\frac{2\times25\times25\times sin20^{\circ} cos20^{\circ}}{110}$
$a=\frac{25\times25\times sin40^{\circ}}{110}$
$a=3.64m/s^{2}$