How much time will elapse between seeing lightening and hearing the thunder happening 8000 m from you?

Answer 1

The flash and the sound happen at the same time, but both the light and the sound have to travel to you, at different speeds.

For fun, or extra credit, you could calculate how long the light takes to travel 8000m, but it's small enough that we can ignore it, especially given the uncertainties in the speed of sound.

Sound travels through air at different speeds depending on the temperature and composition, but you can take 340 m/s as an easy to remember number (just over a km in 3 secs) unless your text specifies somethng different.

So at 340 m/s, hw long does it take the sound wave to travel 8000m?