Final answer:
The steam turbine of a railroad engine works by converting heat energy from the boiler into mechanical energy to drive the train.
Step-by-step explanation:
The subject of this question is Physics. The steam turbine in a railroad engine works by converting heat energy from the boiler into mechanical energy that is used to drive the wheels of the train. The water in the boiler is heated by a fire and turned into steam, which creates pressure that pushes the pistons and drives the train.