The stopping sight distance $\text{(SSD)}$ for a level highway is $\text{140 m}$ for the design speed of $\text{90 km/h}$. The acceleration due to gravity and deceleration rate are $\text{9.81 m/s$^{2}$}$ and $\text{3.5 m/s$^{2}$}$, respectively. The perception/reaction time (in $\text{s}, \textit{round off to two decimal places}$) used in the $\text{SSD}$ calculation is ________________________