posted by Matt .
What constant net force is required to bring a 1500 kg car to rest from a speed of 100 km/h within a distance of 55 m?
100 km/h = 100000m/3600s = 27.8 m/s
Vf^2 = Vi^2+2as
The final velocity, Vf, is 0
0 = (27.8m/s)^2 + (2)(55m)(a)
Solve for the acceleration, a.
F = ma
Use the acceleration from the previous step and the mass given to get the force, F.