A explosive

[karel1987]

I hear a lot about homemade explosions. What if i make a explosive with 20 cobras and put that under my heart ?

 

[Praestat_Mori]

What are 20 cobras?

 

[karel1987]

Vlaamse jongeren vieren oud en nieuw met ‘halve handgranaten’

Vergeet de onschuldig knetterende petards, jongeren spelen vandaag met grover geschut. Cobra heet het nieuwe hippe knalding. Op TikTok wemelt het van de video’s waarop Vlaamse feestvierders tijdens oud en nieuw zulke vuurwerkbommen afsteken, al zijn die illegaal.

www.demorgen.be

Its firework

 

[avoid]

TNO, a Dutch non-profit research organization, published a report in 2017 on the chance of ear and lung injuries that officers in full or partial gear risk when a Cobra (incl. 6 and 8) [wiki] or other illegal firework explodes at a certain distance. [source] Their tests includes a minimum distance of 0.5 meters so I'm not sure if this rapport is of any use to you. But it offers some interesting graphs such as the lethality curve of (blast) overpressure on page 21. Page 35 shows a graph with the measured overpressure as a result of detonating a Cobra 8 at a distance of 0.5 meter, which they estimate to be on par with 63 grams of TNT explosive material in terms of the overpressure it produced. I assume you can't simply multiply this figure by 20 so you'll need to find the correct formula to calculate the overpressure [kPa] that 20 Cobra 8's would generate at a certain distance and positive phase duration [milliseconds].

I don't know the number of Cobra's required to make death certain. I'm not familiar with any lethal cases that involve Cobra's though I'm sure there are some if you Google them.

Edit:
Personally, I would not risk it. Even if your math is correct and 20 Cobra's are theoretically lethal to you – take your weight and body type in account – you can't trust firework to be reliable. According to the report, the shockwave (positive phase) duration of a Cobra 8 is but a few milliseconds (less than 5). I highly doubt you'll be able to detonate all 20 Cobra's or however many you need within a few milliseconds of one another. I'm sure there's some number that may guarantee your death but is it 10, 20, 50 or in the 100s? And creating a bomb of your own is worse unless you happen to have knowledge on how to make bombs, in which case you probably wouldn't ask this question. My advice: don't use fireworks or explosives in general.