A+B together allows us to make the impact force internal (and not appear in the linear impulse-momentum equation). FBDs for A and B individually allows us to determine the t-direction components of ...

Yes, the fake force is a vector. Don't forget about that. Equilibrium. If we are looking at an accelerating car in the frame of the car, then it is at equilibrium.

Equation (9) is equivalent to assuming that the averaged momentum per photon is given by the Minkowski momentum or canonical momentum 13, K=ε r G=G+M, as the total propagating momentum.

A+B together allows us to make the impact force internal (and not appear in the linear impulse-momentum equation). FBDs for A and B individually allows us to determine the t-direction components of ...