Final answer:
The boxes or cabinets located every 800 ft along the right of way and at the end of the station platforms are known as signaling relay cabinets. They house various electrical equipment used for train control and signaling systems.
Step-by-step explanation:
The boxes or cabinets located every 800 ft along the right of way and at the end of the station platforms are known as signaling relay cabinets. These cabinets house various electrical equipment used for train control and signaling systems.
Within these cabinets, you can find relays, switches, circuit breakers, power supplies, and other components that are used to control the signaling system. The signaling system ensures the safe and efficient operation of trains by providing information about track occupancy, train movement, and communication between trains and the control center.
The relay cabinets are strategically placed to ensure proper functioning of the signaling system and to maintain track safety. They are designed to withstand weather conditions and provide easy access for maintenance and troubleshooting. Signal boxes or electrical cabinets are part of railway signaling or electrification systems. The observed frequency changes for a stationary person due to the Doppler effect, but remains constant for the train's engineer.
The boxes or cabinets located every 800 ft along the right of way and at the end of the station platforms are likely referencing signal boxes or electrical cabinets that are part of the railway signaling system or possibly housing equipment for the electrification of the tracks for light rail or train systems. Signal boxes are used for controlling signals and switches to manage train movements, ensuring safety and efficiency on the rails. Electrical cabinets may contain the necessary equipment to distribute power along the tracks or to the trains themselves.
Regarding the scenarios presented, when considering the phenomena of frequencies observed by a person as a train approaches and then passes, we're discussing the Doppler effect. The frequency observed increases as the train approaches due to the compression of sound waves, and decreases as the train moves away due to the stretching of the sound waves. The train's engineer, however, always hears the same frequency because they are moving with the source of the sound.