@gonn92
The math is wrong, though, it's actually less than that (heh) because the guy forgot to divide by 2 (and rounded, but that's no big deal).
The easiest way to do it is to just calculate the kinetic energy of the system right before impact (KE = 0.5mv^2 = 15125J) and compare it to the kinetic energy of the system after impact (0) and that's your answer (15125J ~ 3.6g of TNT). If you want to do it using kinematics, you have v = 55 = at and distance d = 1 = 0.5at^2 -> time to decelerate t = 2/55 ~ 0.036, not 0.2, and a = 1512.5 m/s^2 hence work W = F*d = m*a*d = 10*1512.5*1 = 15125J.