Introduction[]
In My Hero Academia, Todoroki uses his Giant Ice Wall to defeat Hanta Sero, then he vaporize the whole ice shortly after. Credits to iwandesu for the measurements.
Calculation[]
First we need to find the volume of the ice. We only have half shots of the ice one from inside the colliseum and the other from the outside. We'll assume the second one starts right after the first one.
Scan 1
Hanta Sero = 177 cm
Hanta's Head = 23.6 cm or 7 px
Ice Length = 516 px or 17.40 m
Ice Height (First Part) = 543 px or 18.31 m
Now for the second part: For this one we'll assume the size of the line that byssects the dome is equal either inside or outside.
Scan 2
Maiku's heigth is 185 cm, but considering how his hair is actually bigger than his head, I'll just add half a head and halve this by 8. Instead of 7.5, making his head 23.125 cm.
Maiku Head = 10 px or 23.125 cm
Line = 31 px or 71.6875 cm
Scan 3
Here the line is 19 px.
Meanwhile the ice width is 192.44 px and the heigth of the second part is 441.39 px making them:
Ice Width = 7.26 m
Ice Height (Second Part) = 16.65 m
Total Ice Heigth = 18.31 + 16.65 = 34.96 m
We put these values on this Elliptical Cylinder calculator to get the volume.
Ice Volume = 3468.54 m^3 or 3468540000 cm^3
Density of ice is 0.92 g/cm^3.
Ice Mass = 3468540000 x 0.92 = 3191056800 g
Now we can calculate the energy needed to vaporize this amount of ice.
Heat of Fusion = 334.16 J/g
Heat of Vaporization = 2257 J/g
Specific Heat of Ice = 2.108 J/g
Specific Heat of Water = 4.186 J/g
Specific Heat of Steam = 1.996 J/g
ΔT1 = 10°C
Energy = 10*2.108 = 21.08 J/g
ΔT2 = 100°C (Boiling Point)
Energy = 100*4.186 = 418.6 J/g
ΔT3 = 20°C
Energy = 20*1.996 = 39.92 J/g
Total Energy = 334.16+2257+21.08+418.6+39.92 = 3070.76 J/g
Yield = 3191056800*3070.76 = 9798969579168 Joules, 2342 Tons of TNT
Final Tally[]
Todoroki took a while to vaporize all the ice, and the agreed timeframe was 5 minutes, or 300 seconds.
Todoroki Vaporizes Ice = 2342/300 = 7.80 Tons of TNT (Large Building level+)
Since the feat was quite casual, Todoroki's Half-Hot attack potency should be City Block level.