Um...your math is wrong on the dimensional analysis to convert km/hr to m/s; the math would go 840 km/hr * (1000/60) m/s. I put that into my computer's calculator to get 1.4 * 10^4 m/s. With this in mind, I shall continue the calculations with your figures for mass; I do not have a triple beam balance to accurately measure the mass of my 1/144 HG Star Build Strike.Compass wrote: 2.88m joules = 1/2mv^2
v^2 = 64
v = 8m/s
So yeah, it shouldn't have been thrown against the wall
Also, this implies that Luang is on a surface with no friction too, i.e. in space.
There goes any hope of awesome Gundam Baseball
So, the energy the SBS puts into the ball is given by KE = (1/2) * mv^2 = 0.5 * 100 * (1.4 * 10^4)^2 = 9.8 * 10^8 J.
Then, assuming all energy is transferred to Luang's suit, in the same way you described:
9.8 * 10^8 = 1/2 * mv^2; so, v = sqrt([2 * 9.8 *10^8]/m) (let's assume no negative velocity, though there is a negative part in the square root function)
So, v = 4666.7 m/s at the scale of the two kits in question; dividing by 144 to get it into reality (the 1/1 scale as opposed to the 1/144 scale) nets roughly 32 m/s.
However, I do not discount that my math may be wrong.