What is Mach Number? | LEARN?

The Mach Number is like how fast something is moving compared to sound.

Imagine you're on a playground, and you run as fast as you can. If your friend throws a ball at the same time you start running, and it catches up to you, that’s like moving slower than sound. But if you’re so fast that the ball seems to go by you in an instant, that's like moving faster than sound.

Now think about airplanes. When they fly really fast, especially when they're zooming through the sky, we use the Mach Number to describe how fast they are going compared to how fast sound moves in the air.

• If a plane is flying at 1 Mach, it’s moving at the same speed as sound.
• If it's flying at 2 Mach, it’s twice as fast as sound!
• That’s like running two laps around the playground while your friend just throws one ball, you're really zipping through the air!

So the next time you hear a loud boom from a plane, it might be going faster than sound, that's flying at supersonic speed, or higher than 1 Mach!