Fireworks.

[sandyRoe]

If you see the flash of a rocket and 3 seconds later hear the report of the explosion how far away is it?

[bhg481]

5 seconds per mile, so just over half a mile in that case.

[retrocop]

I am not sure you can tell that ,sandy,with pyrotechnics. I would guess the flash of the rocket would be the propellant and the bang would come later from an explosive component within the rocket set to explode at a certain time/height like a proximity fuse.A little different from time the lightning and boom in a thunder storm.

[andres]

approx. 1,030m