Final answer:
The position to which the master controller handle has been moved by the train operator determines the motion and speed of the train.
Step-by-step explanation:
The position to which the master controller handle has been moved by the train operator determines the motion and speed of the train.
In a train, the master controller handle is used to control the electric power that is supplied to the traction motors. By moving the handle to different positions, the train operator can increase or decrease the power, which affects the train's speed and acceleration.
For example, if the handle is moved to a higher position, more power is supplied to the traction motors, resulting in an increase in the train's speed.