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There are a lot of factors in this that can make that work or fail. Among them is the weight of the train, speed the train is going before stopping, the grade, and weather conditions. If your train is a heavy coal train going down a steep grade, then that can be nearly if not impossible to stop on a dime.
There is one more factor that is related to the particular locomotive e-spec, or engine-spec. This is a config file that contains all the parameters for motor speed, braking strength, and other things that go into calculating the operation of the locomotive and thus the movement of your train.
So unfortunately, there's no one set answer. If you are interested, play around with the Test-track. This is available off of the Launcher and will launch a mini-Trainz version where you can place a simple track, setup grades, and place a locomotive, meaning diesels-only at this time.
Once you've got things setup, you can adjust the parameters mentioned, and then save that as a custom engine-spec that you can use later for your locomotives.
