Final answer:
The distance between stations F and N during the fireworks display is the horizontal displacement of the fireworks shell at its explosion point, which is 125 meters.
Step-by-step explanation:
To determine how far apart stations F and N are during a fireworks display, we can look at the provided horizontal displacement of a fireworks shell. It is mentioned that the shell is set to explode at its highest point, which is 125 m away horizontally. This information gives us the distance between the launch station and the explosion point. If stations F and N are aligned with the launch and explosion points respectively, the distance between them would be 125 meters.