Urgent!! I really need help please! Sorry for posting this question again. Lemme try to rephrase my question if it helps . Please help me get started on this question. I am really stuck and time is running out!! I don't want the answer, I just need some pointers to get me going and headed in the right direction. A particle moves in an inverse cubic, central, conservative force field. The force is F = -Amr^-3, where A = some constant, m = mass of particle (pt. mass) r = distance I know that the angular momentum L (its 3 components) are conserved under a central force. The total energy is also conserved since the force is conservative. L = m r^2 θ' E = (1/2) m (r')^2 + (1/2) m r^2 θ'^2 + V(R) The 2 equations above are written in polar coordinate form. Is V(R) = - / F? (/ = integral...sorry) How should I go about in describing the possible orbits of a particle moving under the influence of such a force? I have to consider the following cases: E = 0, E < 0, and E > 0, for non-zero angular momentum cases. I need some desperate guidelines to get me started. Please give some advices. Thanks in advance!