If a dipole, starting from rest and initially pointing opposite to an external magnetic field, is slightly perturbed, it will rotate in order to point in the same direction of the external magnetic field $($its lowest potential energy state$),$ with its potential energy changing to kinetic energy $($just like a ball given a slight push at the top of a hill rolling into a valley$).$ Considering this energy conversion, what is the angular speed of the dipole moment as it passes through its lowest potential energy state $($when it points in the same direction as the external magnetic field$)?$