Given, initial velocity of vehicle u=36km/h =10m/s Stopping distance of vehicle s=5m and mass of vehicle m=2000kg So, from equation of motion v2−u2=2as since, final velocity of vehicle v=0 and acceleration of vehicle =−a (acceleration) ⇒−u2=−2as ⇒a=
u2
2s
=
10×10
2×5
=10m/s2 The average force for braking F=ma=2000×10=2×104N