I’ve been still thinking about the sound. How a gunshot makes its sound.
I had to learn philosophy in high school, and remember a couple of things. Dialectics for example. And when the quantity turns to quality. Let’s try this way. Velocity dependent processes. Each system has (at least one) charasteristic relexation time. When we compress the air slowly, no sound occurs. But do it faster and faster. Molecules collide onto each oder quickly. But it is not like they collide to the rigid wall, cuz the pushed molecules start moving and they collide to the next molecules. So it is not just an instant thing, these subsequent collisions take some time. Grumble? What is the right word? Then the barrel emphasises some frequencies like a whistle does.
We don’t have to solve a differential equation, since it is not given (yet). Probably someone knows it already. (It might be the opposit of, what Feynman called the equation of dry water.)