8.22 nk A particle of mass m moves with angular momentum 43 about a xed force center with F (r) = k / r3 where k can be positive or negative. (3) Sketch the effective potential energy Ueff for various values of k and describe the various possible kinds of orbit. (1')) Write down and solve the transformed radial equation (8.41), and use your solutions to conrm your predictions in part (a)