A star with an initial radius of 1x10^8m and a period of 30 days collapses suddenly to a radius of 1x10^4m. Find the period of rotation after collapse. Find the work done by gravity during the collapse if the mass of the star is 2x10^30 kg. What is the speed of an indestructible person standing on the equator of the collapsed star?
2.6x10^-2 s, 2.3x10^42 J, 2.4x10^6 m/s
2.6x10^-2 s, 2.3x10^42 J, 2.4x10^6 m/s