Asupernova results when a star that has used up all of its fuel undergoes an extremely violent explosion and its mass is blown outward. consider the star, before the explosion, to be a solid sphere of radius r rotating with an angular speed of 2.0 rev/day. once the star explodes its mass rapidly expands into a spherical shell. assuming that all of the star's mass is contained within this spherical shell and there are no external torques acting on it, what is the angular speed of this mass when the radius of the spherical shell is 5.8r?