I know about the addition of velocities for SR v = (v1+v2)/(1-v1*v2/c^2). This equations is derived using Lorentz transformations. How do I derive the addition of velocity formula for particles in a non-inertial frame? Can I just add gammas? u = (u1+u2)/(1-u1*u2/u0^2) where u1 = gamma*v1 u2 = gamma*v2 u0 = gamma*c Or is this too naive? Thanks.