d
\(\begin{array}{l}
Giverr.\,mass\,of\,car\,m = \,1000\,kg\\
u = 30\,m/s\\
v = 0\,m/s\\
retarding\,force\,f = 5000\,N\\
\therefore \,retardation, - a = \frac{{5000}}{{1000}} = 5m/{s^2}\\
By\,equartion,\,{v^2} - {u^2} = 2as\\
0 - {\left( {30} \right)^2} =  - 2 \times 5 \times d\\
\therefore d = \frac{{900}}{{10}} = 90\,m\\
and\,a = \frac{{v - u}}{t}\therefore t = \frac{{v - u}}{a} = \frac{{0 - 30}}{{ - 5}} = 6s
\end{array}\)