When a sound source is moving, it makes understanding sound waves a bit tricky.

Here's what you need to know:

• Changing Frequency: When the source gets closer to you, the sound waves become more frequent, which means the pitch gets higher. This is called the Doppler Effect. When the source moves away, the sound waves become less frequent, and the pitch drops.

• Difficulties: Figuring out exactly how much the frequency changes can be really hard. This is because the speed of the source and the distance can be different each time.

To make it easier, we can use a formula called the Doppler formula. It looks like this:

$f' = f \frac{v \pm v_0}{v \mp v_s}$

This formula helps us understand how the speed of the source and the observer affect the changes in frequency.