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AR15.COM
2/7/2007 6:46:41 PM EDT
Ok, So i've heard everything from 1 second from flash to sound = 1 mile to SEVEN seconds from flash to sound = 1 mile. So what is it?
2/7/2007 6:47:27 PM EDT
[#1]
Do you really think it takes 7 seconds for sound to travel a mere 5,000+ feet?
2/7/2007 6:48:04 PM EDT
[#2]

Quoted:
Do you really think it takes 7 seconds for sound to travel a mere 5,000+ feet?

Not at all, just want to know.
2/7/2007 6:48:38 PM EDT
[#3]
Yes.
2/7/2007 6:52:48 PM EDT
[#4]

Quoted:

Quoted:
Do you really think it takes 7 seconds for sound to travel a mere 5,000+ feet?

Not at all, just want to know.


I would wager it takes about 4.9 seconds

Somebody has earth science HW due tommorow eh?
2/7/2007 6:54:29 PM EDT
[#5]

Quoted:

Quoted:

Quoted:
Do you really think it takes 7 seconds for sound to travel a mere 5,000+ feet?

Not at all, just want to know.


I would wager it takes about 4.9 seconds

Somebody has earth science HW due tommorow eh?


+1  

General rule of thumb is 5 seconds to a mile.
2/7/2007 6:55:01 PM EDT
[#6]

Quoted:

Quoted:

Quoted:
Do you really think it takes 7 seconds for sound to travel a mere 5,000+ feet?

Not at all, just want to know.


I would wager it takes about 4.9 seconds

Somebody has earth science HW due tommorow eh?


Haha, no, i just saw something about it in a different thread and wanted an authoritative answer.
2/7/2007 6:55:32 PM EDT
[#7]

Quoted:
Yes.


Gee, thanks for all the help.
2/7/2007 7:01:33 PM EDT
[#8]
www.onlineconversion.com/

1mile = 5280 ft.
Speed of sound(air) = 1116.437 ft/sec.

5280/1116.437 = 4.729 seconds for sound to travel 1 mile.


I've always heard the "7 second" rule all my life , but the calculator says different.
2/7/2007 7:02:08 PM EDT
[#9]
5280 feet per mile.  Speed of sound in normal atmosphere is 1129 feet per second.  Light travels 764,000,000 feet per second.  Work the math.
2/7/2007 7:03:08 PM EDT
[#10]
sound speed at sea level, standard day, = 1116 ft/sec.

1 mile is 5280 feet.

you do the math...



EDIT :   clearly my typing is too slow for the lightning fast responses of others.
2/7/2007 7:05:46 PM EDT
[#11]
Thanks a ton guys!
2/7/2007 7:05:46 PM EDT
[#12]
speed of sound 340.29 m/s = 1116.43 ft/sec

1 mile = 5280 ft

5280 / 1116.43 = 4.72 sec

so approx 5 seconds per mile
2/7/2007 7:24:58 PM EDT
[#13]
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy
2/7/2007 7:29:54 PM EDT
[#14]

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  
2/7/2007 7:36:09 PM EDT
[#15]

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


lol.  approximately 4 of us that are online right now would know what a diffeq is.
2/7/2007 7:38:46 PM EDT
[#16]

Quoted:

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


lol.  approximately 4 of us that are online right now would know what a diffeq is.


Ohhhh "US" so we have 50% of the smart people on the board right here! w00t!
2/7/2007 7:42:33 PM EDT
[#17]

Quoted:

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


lol.  approximately 4 of us that are online right now would know what a diffeq is.


I guess the rest are all all tired and shagged out from posting in the "airplane on a conveyer belt" thread.
2/7/2007 7:59:44 PM EDT
[#18]

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


Hell no.


I'm looking forward to when I graduated and never have to look at one of those things again.
2/7/2007 8:21:43 PM EDT
[#19]

Quoted:

Quoted:

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


lol.  approximately 4 of us that are online right now would know what a diffeq is.


I guess the rest are all all tired and shagged out from posting in the "airplane on a conveyer belt" thread.


For extra credit, what if the lightning strikes the airplane on the conveyor belt  BTW, I finished off the last class for a math minor last semester so I'm never even going to contemplate a differential equation ever again....    just going to sit around and watch NASCAR and drool on my sleveless flannel...
2/7/2007 8:31:07 PM EDT
[#20]

Quoted:

Quoted:

Quoted:

Quoted:
The speed of sound is much slower at 30,000 feet or so, which is where most lightning occurs.  Most lightning doesn't strike the ground.

-Troy


True, but the sound has to travel through the lower atmosphere to get to you.  Please post the differential equation solution for the sound time from a lightning flash at 30K, including the slant range and wind effects.  


lol.  approximately 4 of us that are online right now would know what a diffeq is.


I guess the rest are all all tired and shagged out from posting in the "airplane on a conveyer belt" thread.



That thread is full of retards and most of them are pilots with reading comprehension problems.
2/7/2007 8:37:41 PM EDT
[#21]

Quoted:
Most lightning doesn't strike the ground.


Maybe not, but when it strikes close, it certainly gets your attention.  

www.petenelson.com/Photos/Misc/House%20in%20Austin/Storm%2C%2010-04-2004/TexasThunderstorm_10042004_05.wmv

I've had other storms where I've been sitting at the computer and it's like a flashbang going off.  
2/7/2007 9:15:29 PM EDT
[#22]
If the storms that bad....dont stand there with a stopwatch to see how far away it is!  Just do like I do and go outside and look