Edit: corrected this forgot the half.

KE = 1/MV2

1/2 * 5000kg * 141m/s * 141M/s = 50,405,000 joules

5 metric tons at 509 km/h is 50MJ

So that bit is correct .. you botched something in your conversion

Last edited by Orac; 12/23/15 01:11 AM.
I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.