Rodent Wars Forum

(Happens around 2:17.)


By melting
Assuming that all the energy comes from the lasers (which seems quite reasonable), then the blast probably has a minimum energy sufficient to melt at least 100g of iron.

Melt energy of iron = roughly 1.28 MJ/kg (1.28 kJ/g)

1.28 x 100 = 128kJ


By KE
The largest chunks are about, conservatively, five inches (0.127 m) across. The density of iron is roughly 7870 kg/m^3, so each one has a mass of ~16 kg. I'll guess that's one-quarter of the total mass flung away, and the average velocity is about 0.3 m/s, so...

(1/2)(m)(v^2) = 0.5 x 64 x 0.3^2 = 2.88J

This is clearly a minimum.