[mmaunder]

To generate the force of a 1 ton TNT explosion, a shell shaped bomb moving at 800 ft per second will need to weigh 311,000 pounds. [K.E.=1/2 x m x v x v]

It takes a fraction of this to dent a tank out of commission, provided you're accurate. The overpressure wave bouncing around inside the tank cabin created by a direct hit probably has stunning effects on the crew and may not kill them if the cabin isn't crushed - although it could do terrible damage to the ears, lungs and stomach.

[JofArnold]

Or to look at it another way:

v^2 = u^2 + 2as = 0 + 2 x 9.81 x 2,000 = 39,000

KE = 0.5mv^2 = 0.5 * 300 * 39,000 = 6MJ

I.e. about 1kg of TNT. "Crush"?? I'm with you on this one, mmaunder

[icegreentea]

For another comparison, modern KE sabot anti-tank rounds (what tanks shoot at other tanks) use penetrators weighing from 4 to 8kg, with a muzzle velocity of around 1500m/s, giving a low of end of ~9MJ. Granted, this is ignoring air friction, and must punch through the front armor (much much thicker) than the top armor that bombs go through.

Also... as a cost comparison, JDAM (the US GPS guidance) kits cost 20-30k per kit (you strap them onto 'dumb' bombs). For the actual bomb itself, you're talking on the range of a buck or two per pound... the inert training versions are much cheaper than that. Explosives are cheeapp. Silicon is pricey.

See link below for pricing information! (The Mk-84 is the 2000lb 'dumb' bomb, it's listed along with its training/concrete version).

http://www.fas.org/man/dod-101/usaf/docs/munition-cost-11-1....

[AdamTReineke]

Just a thought, but if the silicon is expensive, could you potentially engineer the majority of the computerized parts into a UAV that could detach at the last moment and fly back?