A car moving along a straight highway with speed of 126 km/hr is brought to stop with in a distance of 200m. What is the retardation of the car

 $$\begin{gathered} given initial velocity of car =u=126km/hr\Rightarrow 126\times \frac{5}{18}m/s^2\Rightarrow 35m/s^2 \\ The car finally comes to rest so V=0 \end{gathered}$$  

$\begin{array}{l} \\ From kinematics equation v^2-u^2=2as\\ acceleration=a=\frac{v^2-u^2}{2s}\\ a=\frac{0^2-{35}^2}{2\times 200}\\ a=-3.06m/s^2\end{array}$