Given,
Mass of the car, m=200 kg
Initial velocity is u=20.0 m/s
Final velocity is v=8 m/s.
The force on the car is F=7800 N.
Let a be the decelaration,
Thus,
F=ma
a=F/m=7800/200=39
Thus the decceleartion is
[tex]-39m/s^2[/tex]Using the equation of kinematics,
[tex]\begin{gathered} v=u+at \\ \Rightarrow8=20+(-39)t \\ \Rightarrow t=0.307\text{ s} \end{gathered}[/tex]Thus,
The time required is 0.307 s.
