The sound of an artillery gun salvo was heard 20 seconds after the flash appeared.

The sound of an artillery gun salvo was heard 20 seconds after the flash appeared. Determine the distance between the observer and the implement.

Obviously, the distance that the sound of a gun salvo will cover in 20 seconds will be the answer to our task. The speed of sound in air depends on weather conditions and ambient temperature and is about 340 m / s at + 20 ° C. This means that under these conditions the sound of the gun will pass – 340 m / s * 20 s = 6800 m. Therefore, 6 kilometers and 800 meters separate the observer and the artillery gun.