Help, calculating effects of small-arms fire

[His Divine Shadow]

What would a 5, 50 and 500 Kilojoule of mostly thermal energy(a blaster that is) blast do to a human and to say a wall of rock, concrete and steel?

How much energy would it take to make head sized craters in a wall of rock(as seen in ANH when the MF is trying to escape from the planet)?

[His Divine Shadow]

Also I found out that a 9mm Browning Short bullet travelling at 450m/s will impart about .7kilojoules of kinetic energy.

The 5Kj figure is low-end for the blaster pistol from Lord Edam site, I wonder if that could have been around what was required to hurt Leia the way it did?

[kojikun]

I think Mike would comment that energy is irrelevant without time. Even a million joules would do no harm if they're applied at 100 watts for a period of 10 thousand hours. And it also depends on the energy density (100W/cm2 is 10,000 more dense and does more damage then 100W/m2, yet contains the same amount of power), as well as energy absorbtion and dissipation rate (space shuttle thermal insulators absorb and dissipate heat extremely slowly, so while theyre at many hundreds of degrees you can hold them in your hand; whereas aluminum foil absorbs and dissipates incredibly quickly so you can stick a piece of tinfoil in a 400 degree oven and remove it barehanded without getting burned because it cools to room temperature quicker then you can blink)

[kojikun]

Also, transfer medium is important. You said thermal in your first post, but blasters cant possibly work on thermal energy transfer. There needs to be something else, otherwise you would simply burn like if molted steel were poured on you. Blasters seem to utilise an explosive bolt that is also very hot. ::

[Einhander Sn0m4n]

Energy density seems very high with blaster bolts, as their duration is very short (ballpark about 1/15 sec.) I for one wouldn't wanna get hit by anything that has 5Kj packed into such a timeframe, to say nothing about the 50 and 500(!)Kj bolts. Lata and Happy Blaster-bolt Dodging!

[Darth Wong]

You can kill someone with 100 J of energy by hitting him with a knife. You can kill someone with even less than that by using electrical shock.

It depends on how the energy interacts with your body. The 3 kJ of a typical high-velocity bullet is dangerous not because it's 3 kJ, but because the bullet is focused and hardened. It is much harder than your skin, so it tears flesh apart on contact.

Take that same 3 kJ and apply it across your entire chest (ie- by using hard-plate armour), and you'll be fine. If you want to know about THERMAL effects, I'd suggest looking up radiation-burn energy figures for first and second-degree burns. Keep in mind, however, that the Rebel commando team was probably wearing some kind of flexible thermal insulator body armour (I'm sure most Trekkies would assume Leia is naked when they perform calculations).

[Uraniun235]

Hmm, that'd be nice, to have Leia naked in front of us while we do calculations...

[kojikun]

Mike, do our similar replies mean I can be one of your evil minions? :3

[His Divine Shadow]

I think Mike would comment that energy is irrelevant without time. Even a million joules would do no harm if they're applied at 100 watts for a period of 10 thousand hours. And it also depends on the energy density (100W/cm2 is 10,000 more dense and does more damage then 100W/m2, yet contains the same amount of power), as well as energy absorbtion and dissipation rate (space shuttle thermal insulators absorb and dissipate heat extremely slowly, so while theyre at many hundreds of degrees you can hold them in your hand; whereas aluminum foil absorbs and dissipates incredibly quickly so you can stick a piece of tinfoil in a 400 degree oven and remove it barehanded without getting burned because it cools to room temperature quicker then you can blink)

I don't think such nitpicking would be required, since we're talking about weapons here, and I believe I hinted at me talking about blaster weapons wich would impart their energy in less than a second and in a small area, so I see no need to point that out unless you want to show off your huge mind and all the information it contains

[His Divine Shadow]

Take that same 3 kJ and apply it across your entire chest (ie- by using hard-plate armour), and you'll be fine. If you want to know about THERMAL effects, I'd suggest looking up radiation-burn energy figures for first and second-degree burns. Keep in mind, however, that the Rebel commando team was probably wearing some kind of flexible thermal insulator body armour (I'm sure most Trekkies would assume Leia is naked when they perform calculations).

The 5-50-500KJ per shot figures for blasters comes from Lord Edams site and his assumptions on the power bars , it gives 5-50KJ for Han Solos DL-44 blaster, though I wonder if that would fit with this:
http://hisshadow.123hostnow.com/misc/me ... escape.avi

What I am wondering, is 50KJ enough to accomplish such feats as shown?
Also figures for the E-11 are 50-500KJ

[Darth Wong]

The 5-50-500KJ per shot figures for blasters comes from Lord Edams site and his assumptions on the power bars

I think you know what I think of those assumptions, particularly when the resulting predictions are so wildly inconsistent with observation.

What I am wondering, is 50KJ enough to accomplish such feats as shown? Also figures for the E-11 are 50-500KJ

1 kg of TNT releases roughly 4.2MJ of energy. Therefore, 50kJ is equivalent to 11 grams of TNT, or less than half an ounce. I've never done demolitions, but I find it HIGHLY doubtful that less than half an ounce of TNT would blow apart steel-reinforced concrete so easily, particularly given the inefficiency of force-coupling from a pure-thermal weapon.

[His Divine Shadow]

I think you know what I think of those assumptions, particularly when the resulting predictions are so wildly inconsistent with observation.

Actually, I don't

1 kg of TNT releases roughly 4.2MJ of energy. Therefore, 50kJ is equivalent to 11 grams of TNT, or less than half an ounce. I've never done demolitions, but I find it HIGHLY doubtful that less than half an ounce of TNT would blow apart steel-reinforced concrete so easily, particularly given the inefficiency of force-coupling from a pure-thermal weapon.

Yes, 11,9grams actually(I reccomend Master Converter if you're lazy, can also be run on linux with Wine, it's got almost everything and you can add your own stuff, it's gold)

[Sea Skimmer]

The 5-50-500KJ per shot figures for blasters comes from Lord Edams site and his assumptions on the power bars

I think you know what I think of those assumptions, particularly when the resulting predictions are so wildly inconsistent with observation.

What I am wondering, is 50KJ enough to accomplish such feats as shown? Also figures for the E-11 are 50-500KJ

1 kg of TNT releases roughly 4.2MJ of energy. Therefore, 50kJ is equivalent to 11 grams of TNT, or less than half an ounce. I've never done demolitions, but I find it HIGHLY doubtful that less than half an ounce of TNT would blow apart steel-reinforced concrete so easily, particularly given the inefficiency of force-coupling from a pure-thermal weapon.

The main destructive effect of TNT comes from the blast wave caused by detonation, not the heat. Though the blast is effectively a by-product of the heat being released.

C-4, Semtex and other plastic explosives are another story. They do work and cause their damage by thermal effects. Effectively the release enough heat to break the molecular bonds of the target material. It basically burns through it.

However the lack of concussive effects makes such explosive of greatly reduced utility aginst area targets or earth. That’s why no one has ever filled torpedoes of aircraft bombs with them.