• We're looking for artists. Direct message Dr. Watson for more info!
Delicious in Dungeon - Undine's water attack
(From chapter 18 of the manga and episode 8 of the anime)

The Undine can shoot spouts of water with enough force to break stone, which several characters can react to. Firstly, we need the rough diameter of the undine, which we can find easily scaled from Senshi a couple of chapters later. Senshi is 140cm tall.
1194 pixels = 140cm
1 pixel = 140cm/1194 = 0.117252931cm
0.117252931cm X 224 = 26.2646565m
30 pixels = 26.2646565m
1 pixel = 26.2646565cm/30 = 0.87548855cm
0.87548855cm = 32.3930764cm

Now let's scale to our feet. Let's find the distance between the undine and Marcelle. Marcelle is 160cm tall.
367 pixels = 160cm
1 pixel = 160cm/367 = 0.435967302cm
0.435967302cm X 504 = 219.72752cm
0.435967302cm X 27 = 11.7711172cm
0.435967302cm X 104 = 45.3405994cm

311 pixels = 32.3930764cm
1 pixel = 32.3930764cm/311 = 0.104157802cm
0.104157802cm X 35 = 3.64552307cm
3.64552307cm/2 = 1.82276153cm

Let's find the distance to Marcelle.
object degree size = 2*atan(Object_Size/(Panel_Height/tan(70/2)))
= 2*atan(367/(634/tan(70/2)))
= 0.535383099 rad
= 30.6751919954108203 degrees

Enter this through the angscaler and we have a distance of 291.68cm to Marcelle. Next we need the distance to the undine.
object degree size = 2*atan(Object_Size/(Panel_Height/tan(70/2)))
= 2*atan(250/(634/tan(70/2)))
= 0.369411799 rad
= 21.1657369850875874 degrees

The distance to the undine in the first panel is 86.689cm. We can now find the distance between the undine and Marcelle.

L = 291.68cm - 86.689cm
= 204.99100cm

Next we need the distance between the pillars and the walls. We can also find the diameter of the hole in the wall.
11 pixels = 11.7711172cm
1 pixel = 11.7711172cm/11 = 1.07010156cm
1.07010156cm X 271 = 289.997523cm

Now we can find the total length of the water beam.

L = 204.99100cm + 289.997523cm
= 494.988523cm (4.94988523m)

Let's find it's surface area (as a cylinder).

A = 2πrh + 2πr^2
= 2 X π X 1.82276153 X + 2 X π X 1.82276153^2
= 5689.85468cm^2 (0.568985468m^2)

Now we have the dimensions of the water beam, let's find the area of the hole in the wall.
1.07010156cm X 10 = 10.7010156cm
10.7010156cm/2 = 5.3505078cm
35 pixels = 10.7010156cm
1 pixel = 10.7010156cm/35 = 0.305743303cm
0.305743303cm X 11 = 3.36317633cm

Volume of the area destroyed as a cylinder.

V = πr^2h
= π X 5.3505078^2 X 3.36317633
= 302.47502cm^3 (0.00030247502m^3)

We see fragments sent flying out, so I think violent fragmentation would be justified. Violent fragmentation of rock is 69000000 joules per m^3.

E = 0.00030247502 X 69000000
= 20870.7764 joules

Impressive, but what we're really here for is the speed. Drag coefficient of a cylinder is 1.17 (and using this calculator to find the square root).

DF = ½ρCAv2 X d
20870.7764 X 2 = 1.17 X 0.568985468 X 4.94988523
V^2 = 41741.5528/3.29520293
V^2 = 12667.3694
V = 112.54940870568801m/s

Final Results
Undine's water beam punctures wall (energy) = 20870.776 joules
Undine's water beam puncture's wall (speed) = 112.549 m/s


Another of it's beams takes out part of a pillar, but unfortunately I can't get a good frame of reference for scaling.
 
Delicious in Dungeon - Kinetic energy of Red Dragons
Red Dragons have a maximum running speed of 60km/h (or 16.6666667m/s). Red Dragons (and also the Chimera Falin) have over 3 tons (3000kg) of edible meat.
KE = (0.5)mv^2
= (0.5) X 3000 X 16.6666667^2
= 416666.668 joules

Final Results
Red Dragon's maximum running speed = 16.667m/s
Kinetic energy of the Red Dragon = >416666.668 joules
 
Gurren Lagann - Nanda-class's length
The Ashtanga is not the only force in the Anti-Spirals fleet...the Nanda-class is a mechanical monster which dwells within the Galactic Spiral Abyss, and is found in the manga, novels and script. It's size is even bigger than that of the moon-sized Super Galaxy Dai-Gurren. Thankfully, I've already done the scaling for the size of Super Galaxy Dai-Gurren, which will make things much easier...
260 pixels = 3474.2km
1 pixel = 3474.2km/260 = 13.3623077km
13.3623077km X 153 = 2044.43308km
13.3623077km X 484 = 6467.35693km
13.3623077km X 51 = 681.477693km
43 pixels = 681.477693km
1 pixel = 681.477693km/43 = 15.8483184km
129 + 92 + 143 + 211 + 95 + 56 + 29 + 59 + 63 + 71 + 95 + 165 = 1208 pixels
15.8483184km X 1208 = 19144.7686km

And the Nanda vanishes off-panel, meaning it's ultimately even longer.

Final Results
Nanda-class's length = >19144.769km
 
yeah the imgur scans are dead