posted by Clare .
A train with a mass 5x10^5 kg is moving with a speed 80km/hr. If the train stops in 2min...1)What is the acceleration of the train? 2) What is the braking force applied to the train?
1. Vo = 80km/h = 80000m/3600s=22.2 m/s.
V = Vo + a*t.
a=(V-Vo)/t = (0-22.2)/120s=-0.185 m/s^2.
2. F = m*a = 5*10^5 * (-0.185)=-92500 N.