Answer:
So net force will be F = 1420×0.985 = 1399.61 N
Step-by-step explanation:
We have given mass of the car m = 1420 kg
Initial velocity of the car u = 12.4 m/sec
As the car finally stops final velocity v = 0 m/sec
Distance after which car is halt s = 78 m
Now according to third equation of motion



Magnitude of acceleration

So net force will be F = 1420×0.985 = 1399.61 N