ds^2 = dt^2(r – r_+)(r – r_-)/r^2 – dr^2[(r – r_+)(r – r_-)/r^2]^{-1} => (1-v^2)/t^2 where t^2 from I=F/dt =>I^2 => t^2=F^2:Impulse^2 => (1-v)(1+v)Impulse^2/mmaa => (1-v)(1+v)/m^2a^2 [...] Read more