I was watching an XKCD “What-If” video recently and Randal off-handedly mentions the title fact as a given. Upon a further Google search I see explanations about why sound moves faster in liquids than gasses but nothing for my specific question. Is there an intuitive explanation for that fact or is it just one of those weird observable facts with no clear explanation
Sound is transferred through a medium literally as a wave. When you get right down to the core of it, the wave requires movement within the medium to transmit.
So it might help to conceptualize it not as “Liquid cannot move faster than the speed of sound in it’s medium” but more like “The speed of sound in a liquid medium is defined by the speed at which energy can propagate in that system, which includes motion.”
So you’re saying I should view the speed of sound in a medium like the speed of light in a vacuum? That it’s the “speed-limit” of how a wave propagates and so trying to exceed it is impossible for a physical wave?
Badically. “Liquid/fluid” and “gas” don’t necessarily mean the same thing scientifically as they do colloquially, they’re actually very close to the same thing.
Fluid dynamics covers the study of liquids, gasses, and plasmas because they’re effectively the same.
Note that the speed of sound isn’t a constant across various media. Just like the speed of light isn’t a constant on different media. The “speed of light” we usually refer to is specifically in a vacuum. Light travelling through a media like water or a prism actually changes speed, however slight.
The same happens to sound. The speed of sound at altitude is different from sea level for instance, because of the atmospheric pressure difference. And sound doesn’t propagate at all in a vacuum because it requires the wave to move molecules, which don’t exist in a vacuum.
So the medium is like a car made of liquid and the speed of sound is a passenger?
No, medium is the speed limit and the sound is a car that drives legaly.
What’s updog?
Nothing dog, whats up with you?
I saw you hadn’t been asked in a while, had to give you the opportunity.
Just to add because nobody mentioned that yet… But you can always push stuff faster than the speed of sound, it will just stop being a liquid, and probably explode, but there’s no law saying the material can’t go faster.
But you can always push stuff faster than the speed of sound
Sure, but said stuff can push back at you in turn, on account of Newton’s 2nd Law. At some point, you reach an equilibrium between the force applied to the material and the reflected force due to resistance.
Does this mean that a drop of water can’t move through air faster than the speed of sound in air?
Or that a drop of water can’t move faster than the speed of sound in water anywhere?
I’m pretty sure they are talking about the 2nd one
Might help to look up the definition of Terminal Velocity.
Terminal velocity is the maximum speed an object can reach while falling through a fluid (like air or water). It occurs when the force of gravity pulling the object down is balanced by the fluid’s resistance, or drag, pushing it up.
As the speed of an object increases, so does the drag force acting on it, which also depends on the substance it is passing through (for example air or water). At some speed, the drag or force of resistance will be equal to the gravitational pull on the object. At this point the object stops accelerating and continues falling at a constant speed called the terminal velocity (also called settling velocity).
How about firing a compressed air canon to attempt a sonic boom
Imagine the liquid as a road, and the sound travelling through it as a runner on said road. Now, sound is faster than the road, because road isn’t moving anywhere. But if we replace the road with one of those airport speedwalking walking pads (kinda like escalators but flat on ground), now the ground is moving, but as luck would have it, the runner is now moving even faster. The more you speed up the pad, the faster the runner moves, even if the runner themselves has not increased their speed.
Weird stuff, but it does make sense. :)
Use a better search like Bing or duckduckgo next time. googol sucks and was never any good. Quit using ignorant garbage.
