In missile launching system, is the feed back element or device.

I have a wooden toy train that runs on wooden tracks. I would like to place two ESP-WROOM-32 Boards on top of the train. Broadcast communication (which involves radio frequency, not Wi-Fi) would help communicate about the train's lateness to five other wooden trains on the same track. Local communication would help communicate to the train station about the train's lateness. I would also need radio frequency Tx-Rx Modules for discharging and undergoing the signal, and repeaters just in case the signal loses power due to long-distance traveling. My wooden train should be automated. It should run at 4 inches per second, keep a minimum distance of 30 seconds away from the other wooden trains, and make a 17-second-long stop every 500 seconds. What's the procedure to connect the components? What's the Arduino code (C++) for this project?

What is the minimum distance between conduits in a junction box straight through pull? A. 6 times the diameter of the largest raceway B. 8 times... C. 10 times... D. 12 times...

Draw a simple pulse detector (positive-edge) diagram and explain how it works.