sentences:  At this time, if the engineer applies too much power to the wheels (i.e., for a steam locomotive, he opens the regulator too far) the turning force applied to the wheel will greatly exceed the opposing friction force affected by the surface of the rail, and the wheel will turn without being able to move the train forward.If the engineer does not take quick corrective action (i.e.by closing the regulator) the locomotive can end up stationary with its wheels spinning