Mass of car, M=2000kg
Velocity, V=72× 5/18 =20ms¹
Apply kinematic equation of motion
v² -u² = as
0 − 20² =2a×20
a=−10ms^-2
Breaking force, F=ma=2000×10=20 kN
Apply first kinematic equation
v = u +at
[tex] t= \frac{v - u}{a} = \frac{0 - 20}{ - 10} = 2sec\\[/tex]