I think it is
Ek=1/2(m)(v)^2
so would I sub in the values like this?
3.1x10^6 J=1/2(750kg)(v)^2
then rearranged I think it would be
v=2Ek/m (the right hand side should have a square root, but I don't know how to make that symbol)Also sorry about the late reply, I was busy with some other IRL...