Consider a particle with mass m and angular momentum l in the field of a central force f= ? k/(r^(5/ to simplify your equations, choose units for which m=l=k=1.a) find the value r0 of r at which ueff is a minimum and make a plot of ueff(r) for 0\leq< 5r0.b) assuming now that the particle has energy e=-0.1 find an accurate value of rmin, the particle's distance of closest approach to the force center. c) assuming that the particle is a r= rmin when ? =0 use a computer program to solve the transformed radial equation and find the orbit in the form r= for ? . plot the orbit. does it appear to be closed?