What is the speed of sound?

1flash then boom

Watch a distant firework: you see the flash first, then hear the boom a few seconds later. Sound is slower than light, but how slow?

2343 m/s

In air at room temperature, sound travels about 343 meters per second. That is roughly 1,235 kilometers an hour, faster than a bullet train.

3storm trick

Here's the trick: count seconds between flash and boom, divide by three, and you get the distance in kilometers. Sound covers about a kilometer every three seconds.

4the surprise

Now the surprise: sound isn't a fixed number. It depends on what it travels through, because sound is molecules bumping molecules, and stiffer, closer-packed stuff passes the bump faster.

5the numbers

Air carries it at 343. Water, packed tighter, about 1,480 meters per second. Steel, rigid as a bell, roughly 5,900. Over four times faster than water.

6warmer faster

Temperature matters too. Warmer air makes molecules zippier, so sound gains about 0.6 meters per second for every degree Celsius. Cold day, slower sound.

7whole idea

So the keepsake: sound is not a speed, it's a speed per material. Air 343, water 1,480, steel 5,900 meters per second, and always slower than the flash of light.