m = mass of the race car = 1200 kg
v₀ = initial velocity of the race car = 175 m/s
v = final velocity of the race car as it comes to stop = 0 m/s
d = stopping distance of the race car = 120 m
a = acceleration of race car while slowing down
using the kinematics equation
v² = v₀² + 2 a d
0² = 175² + 2 a (120)
a = - 127.6 m/s²
magnitude of force required to stop the car is given as
F = ma
F = 1200 x 127.6
F = 153120 N
hence the force required to stop the car is 153120 N