physics
posted by Madeline .
A car traveling 72.0 km/h along a straight, level road is brought uniformly to a stop in a distance of 40.0 m. If the car weighs 8.8 x 103 N, what is the braking force?

(Work done against braking force) = (initial kinetic energy)
F*X = (1/2) M Vo^2
F = M Vo^2/(2 X)
Be sure to convert 72 km/h to 20 m/s before using the formula.