"fires aluminium rounds close to the speed of light"
Discussion
Eraser is at the moment on E4. The rail gun used in this film fires projectiles this fast. This seems a bit optimistic.
As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
Could be a sabot round? I think rail gun rounds have to be like this or else you just vaporize the projectile (especially so with something as weedy as Aluminium).
But does it need to be ferrous? I just needs to conduct electricity, the current in the round would produce the electromagnetic field to interact with the two from the rails surely?
Another problem is, hand held weapon...short rails. So you need lots of energy very fast to accelerate the projectile. It'll just weld or vaporize the projectile. You can try get round this by shielding with injections of inert gas.
close to the speed of light thing is balls though. Sure it would be very quick, supersonic easily. But far from the speed of light.
But does it need to be ferrous? I just needs to conduct electricity, the current in the round would produce the electromagnetic field to interact with the two from the rails surely?
Another problem is, hand held weapon...short rails. So you need lots of energy very fast to accelerate the projectile. It'll just weld or vaporize the projectile. You can try get round this by shielding with injections of inert gas.
close to the speed of light thing is balls though. Sure it would be very quick, supersonic easily. But far from the speed of light.
Tim330 said:
Eraser is at the moment on E4. The rail gun used in this film fires projectiles this fast. This seems a bit optimistic.
As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
It's much worse.As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
Apart from mass needing to be in kg, relativistic increase in mass that close to the speed of light would increase the energy by a huge factor - approaching infinity.
Tim330 said:
Eraser is at the moment on E4. The rail gun used in this film fires projectiles this fast. This seems a bit optimistic.
As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
Grams of kilograms?As this is the the science forum lets assume the bullet weighs 10 grams
KE=1/2MV2
1/2 *10*(299 792 458 ^2)= 449377589368408.8 joules
As a watt is a joule per second this seems like alot of power for a hand held weapon. I've been at the pub so stand to be corrected by any real scientists!
Tim330 said:
As this is the the science forum lets assume the bullet weighs 10 grams
Ignoring the many many other issues- why would you need such an enormously heavy projectile? "IF" you could hit a target with something at that speed you don't need very much weight, mc squared afterall :-)
otolith said:
Maybe someone could calculate how much mass one could accelerate to .9c while generating a tolerable recoil?
Fairly straight forward if we pretend that relativity doesn't exist...12 gauge shotgun slugs generate a fair bit of recoil, ~30g at 500m/s. Same momentum at 0.9c would need the projectile to be about 0.00005g (50 micrograms). Half a grain of sand or so.
(quick sum so apologies for any misplaced powers of 10)
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