Question

The flash of an exploding cracker is seen even before we hear the sound.
Why?​

Answer 1

Answer:

When a lightning strikes it tremendously heats the air around the lightning channel, which has rapidly to expand, which will create a sound wave, similarly to an explosion of a fire cracker, a bomb, or an airplane breaking through the sound barrier, which means exceeding the speed of sound in air, which is about 340 ..