For constant acceleration, you have two equations that you need to solve for time $t$ and acceleration $a$.
$$ x = \frac{1}{2} a t^2 $$$$x=\frac12at^2$$ $$ v = a t $$$$v=at$$
It is up to you from here.
$$ \left(402\, {\rm m}\right) = \frac{1}{2} \, a \,t^2 $$$$402\ \mathrm m=\frac12at^2$$ $$ \left( 190 {\rm \frac{km}{hr}}\right) \left( \frac{1000 {\rm \frac{m}{km}}}{3600 {\rm \frac{sec}{hr}}} \right) = \left(52.777 {\rm \frac{m}{sec}} \right)\, a \,t $$$$\left(190\ \mathrm{\frac{km}h}\right)\left(\frac{1000\ \mathrm{\frac m{km}}}{3600\ \mathrm{\frac sh}}\right)=\left(52.777\ \mathrm{\frac ms}\right)at$$
