POLL: The speed of sound (timed poll)

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Storms!

Fine, it's not day-to-day, and it isn't necessarily that important either (Hear lightning? Disconnect equipment.)... so maybe I was being facetious.

(Sorry if I offended anyone.)

 

Well, aside from the grade school-level of the question, I can't see why it matters all that much whether people think it's 1 mile/second, or 5. Yes, it's important for scientists, but for the vast majority of the population, I doubt it's going to have much impact on their everyday lives...

...unless, of course, you happen to be Superman, it which case you want to be careful that you don't break any windows with your sonic booms. (And if anyone gets into a debate about whether Superman actually creates sonic booms, I'll be forced to hurt them. Badly. )

 

I sure hope junior schools aren't wasting valuable time teaching useless information like the speed of sound (that kids will never use).

 

The problem isn't knowing or not knowing. The problem is misinformation. Thinking you know the right answer but instead being wrong. I don't give a hoot if you don't know what it is, but if you're going to claim you know, especially if you're going to override the answer taught in schools to your kid, you'd damn well better be right.

 

Over here, if you are gonna pass Physics, then you need to know the speed is 330-340 m/s. OTOH, if you have no interest in science then it is pretty useless to you.

 

I am surprised about the percentage of the misinformed ones. I expected something smaller than 10%

 

I have done a straw poll of ten people I work with and none of them has the faintest idea what the speed of sound is.

 

Other than the one-one-thousand, two-one-thousand ... approach to thunder, I've only used the speed of sound for one other application:

'Vampire, vampire bearing 250, 30 nautical miles and closing.'

We knew a missile flying at mach 1 would travel at approximately 10 nautical miles per minute (a nautical mile is 2000 yards vice 1760). Typical Soviet missiles traveled between mach 2 and 3. At 30nm we had one to one and a half minutes before impact.

 

That surely must be "see lightning" (or "hear thunder"). Unless Taza has got some superpowers...

Anyhow, speed of sound in air is nice to know, but not something you can't do without. It took me some time to remember, and even so I am not sure I have the right value ( about 300 meters per second, I think)

 

@khaavern
and how would you propose thunder is formed? (other than lighting)

I didn't vote - (I've locked myself in my room for the last week or so to study for my end of year exams).
But yeah, I vaguely remember the one-hundred, two hundred, three-hundred thing to determine how many metres away from lightning you are. Depending on how fast you say this it could be anywhere between 100 and 300 m/s. The upper limit of this is pretty close to the generally accepted value of 330 m/s.
In year 11 we had to know this for physics as well as the speed in water. This is not however required for the Year 12 curriculum (although we get the odd velocity question based on sound, but in such a case, they have to give us the value).

 

It's more common to define the speed of sound as a function of temperature, although that is of course directly related to the pressure and density. Therefore if you were in Antartica during the winter and would have a temperature of -50 degrees Celsius outside, this would result in the same speed of sound as an airplane flying at 10 km height (where it would also be approximately -50 degrees C).

The generally accepted value of 330 m/s for the speed of sound stems from an average value of the outside temperature of about 15 degrees C. At 25 degrees C it would be approximately 340 m/s.

I always thought the 330-340 m/s value for the speed of sound was something of common knowledge, but I've been known to be wrong on what is common knowledge, forgetting that not everyone has had the same education I had (i.e. not everyone has had physics in high school, or found it interesting enough to pay attention).