the starship enterprise is cruising along at constant speed v when it encounters a mysterious space station. (enterprise = x, space station = S) the enterprise is headed such that it will pass the space station at a distance d, as shown above. the question states: argue that angular momentum conservation does not allow the tractor beam to make the enterprise reach the space station if we treat them both as point particles. given, v_enterprise, d. so.. here's what i tried. system = ship + station; no external torques, so angular momentum is conserved. let l = the top side of the triangle (distance that enterprise would travel if not being pulled by tractor beam) let r = hypotenuse L_i = r X p |r| = sqrt(l^2 + d^2); |p| = mv let the space station be at the origin, therefore L_f = 0 so.. sqrt(l^2 + d^2)*(mv)*sin(phi) = 0; sin(phi) = L/r sqrt(l^2 + d^2)*(mv)*(L/r) = 0 now.. i have absolutely no idea what to do.. could i get a hint, anyone?