. The problem statement, all variables and given/known data A train has a mass of 5.77E+6 kg and is moving at 99.4 km/hr. The engineer applies the brakes, which results in a net backward force of 1.11E+6 N on the train. The brakes are held on for 26.9 s. What is the new speed of the train? How far does it travel during this period? mass of train: 5,770,000 kg speed of train: 99.4 km/hr (i converted it to m/s and got 27.611 m/s) Backwards net force of: 1,110,000 N Brakes held for: 26.9 s 2. Relevant equations f=ma? V=Vo+at? X=Xo+(Vo)(t)+.5at^2? 3. The attempt at a solution I am fairly new to physics and don't really know what I'm doing, anyways...first i used f=ma and got a=.192 then i used that in the second equation and got V=1,110,005.165 N and then I plugged that into the third equation and got 29859069.4666 M but it said i was wrong :/. I am not asking for the answer, just what equations to use and what order to do what in, of coarse if you would like to solve it for me feel free:) -Thanks in advance!