Posted by Devon on .
A freight train has a mass of 5 x 107 kg. If the locomotive can exert a constant pull of 12 x 105 N, how long would it take to increase the speed of the train from rest to 85 km/h

physics 
MathMate,
m=5*10^{7} kg
F=12*10^{5} N
a=F/m m/s²
Time, t, to reach 85 km/h = V m/s (conversion required)
t=V/a seconds