Well spotted I had conveniently ignored that speed is measured in m/s and acceleration is measured in m/s^2 not (m/s)^2.
And indeed I was thinking more about Kinetic Energy than Force.

EDIT: I can't believe I forgot the factor of (1/2) in the Kinetic Energy.
But didn't Albert do the same thing.
Why isn't it E=M(C^2)/2

I haven't seen: E^2 = M^2 C^4 + P^2 C^2 before,
that takes the wind out of next weeks questions on electro magnetic radio waves where I was going to say albert was wrong because E=0*C^2 would equal zero for a massless photon.

But start doing your research because I still have some humdingers on radio waves.