dB

[stanfield]

How many decibels produce an explosion of C-1 (100 g) ?

[Disturbed]

Why? are you trying to determine how loud you have to shout at it to make it detonate or what?

[stanfield]

no, I would like to know how many decibels produce an explosion...

see ya !

[Jumala]

I can not say if it is possible to messure a explosions shockwave in dezibel. It isn´t a continuos sound, only a single wave.
This wave has a tremendous pressure. It can damage windows in some distance to the explosion.
So I think a shockwave has many hundreds of dB.

[Tony Montana]

No No, I know this one,
It takes one decibel to make the explosive,
And another to screw the detonator in!
So it takes two decibels yeah stanfield?
See ya !

[stanfield]

even alone in the desert (Sahara) without someone near you and without wind or something like that, you haven't 2 dB...

[Lagen]

It is really difficult to convert the values of pressure generated by the shockwave to decibels, but this is my guess: It would be 103 dB at 100m, 132 dB at 10m. These values are only approximate, they assume the detonation occurs in an absolutely void space. Any reflections will make them bigger. 100g of your HE detonated in an enclosed area, like a room, tunnel etc. may generate 140+ dB which is sufficient to break your eardrums.

[Mr Cool]

I was just about to point out that you haven't specified the distance.
I hate decibels, they're a stupid unit. So is the Richter scale, because IIRC if you go up one point on the scale the intensity is multiplied by 10. I never saw the point of that, it just makes it more complicated.

[stanfield]

The distance ?
My plastic will be for a "mission" but, more on this when I will take some photo and post them here...
(the distance will be relatively short...)

see ya !

[Disturbed]

Mr Cool,
Yea, the Richter scale does go up by ten. They certainly did a good job of making those things overly complex.
Does anyone here remember how decibels are measured? I know it's some sort of logarthymic scale, where it doubles in intensity for every 10Db. Is that right, or totally off?

[Lagen]

Well that depends what quantity you have in mind. Decibels are used not only in acoustics, but also in electrotechnics in a variety of contexts. In acoustics you use them to either describe the intensity level or the level of acoustic pressure. For intensity: L_I=10.log(I/I_o), where I and I_o are intensities, I_o=10^-12 W.m^-2, for level of acoustic pressure L_p=20.log(p_ef/p_{o ef}). Both of the scales give approximately the same results, as I=(p_ef²/ro*c). And you think that the order of magnitude increase with linear increase of decibels is just a useless complication? It is just an attempt to approximate the way your eyes and ears perceive the outer stimuli that differ in orders of magnitude. Simply said: To you a 40dB sound feels just twice as loud as 20dB, while in fact it has 10 times more pressure and 100 times more watts per unit area! (Ohmigod, hischool physics!)

[Disturbed]

Thanks for all the info Lagen
However, it depends on which highschool physics class you take. If yours was anything like mine, all we did was learn about momentum, acceleration, gravity, etc, and watched movies like 'top gun' and 'the invisible man'.

Not really the best education in physics, unfortunately, although the teacher let me come in during my free periods and work on explosives http://theforum.virtualave.net/ubb/smilies/smile.gif
The only time I ever did anything involving decibels was in pre-calc. There's a chance stuff like that might come up in the advanced calc I'm going to be taking in college shortly...


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