Ford Prefect wrote:Ryan Thunder wrote:Hmm, firepower? They've rammed ships to cause damage, rather than shoot them.
And? Even the smaller ones must mass several hundred thousand tons, and can easily hit thousands and thousands of kilometres a second. That's going to leave a mark.
The rule of thumb is, an object travelling at 3 km/s carries its own weight in BLAM.
I'm going to calculate the energy a smallish 40k ship travelling at 12 km/s carries with it. That's a real crawl, btw, we know 40k ships can do at the very least hundreds of gees of acceleration. For the purpose of simplicity our ship shall be a a block 1x.25x.25 km. We'll assume it's made of 5% iron and 95% air. Note that the real solid proportion is
much higher, and the materials used by 40k make iron look like chalk.
The volume of the block is 62,500,000 cubic metres. Of these, 3,125,000 cubic metres are iron and 59,375,000 are air at 1 atm and 20 degrees C. Iron's density is 7870 kg per cubic m, and air's density at stated temperature and pressure is 1.2 kg per cubic m.
Thus, the mass of our starship is 24,593,750,000+71,250,000=
2.4665E
10 kg
The formula for kinetic energy is half the mass (in kg) multiplied by the square of the velocity (in m/s). We have the mass, and the velocity is 12 km/s = 12,000 m/s. The square of the velocity is thus 144 million metres per second. So:
KE=
2.23325E
10 x 144,000,000
KE=
3.21588E
18 Jules
So the kinetic energy is basically 3.2 exajules. Since a megaton of energy is defined as 4.184 petajoules, our ship carries with damn near one gigaton of energy.
But wait! We were using a ludicrously conservative velocity. What happens if the ship were travelling a hundred times faster? Well, that's 1200 km/s = 1,200,000 m/s, the square of which is
1.44E
12 m/s. We substitute that for our old 144 million m/s and we get:
KE=
3.21588E
22 Jules
That's 32 exajules, in other words, our ship just hit the other with a whopping
7.7 teratons.
In short, Ryan Thunder can take his ignorance and shove it.