< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > A 50,000kg locomotive is travelling at 10m/s on a level track when the engines and brakes both fail. If there is a frictional force of 142N acting to slow it down, how far will it roll before it stops? a=F/m t=v/a d=vt a=142N/50,000kg a=2.84*10^-3 t= 10/2.84*10^-3 t=3521 sec d=10*3521 d=35211 metres Stopping distance = 35.21 km? This sounds way too long. Can anyone point me in the right direction?