Density remaining constant, if earth contracts to half of its present radius, duration of the day would be (in minutes)

Mass remaining constant, if the earth suddenly contracts to one third of its present radius, the length of the day would be shorted by

Mass remaining constant, if the earth suddenly contracts to one third .of its present radius, the length of the day would be shortened by

If Earth contracts to half of its present radius what would be the length of the day at equator?

If the radius of the earth contracts to half of its present radius , then the length of the day will be (if the mass of the earth remaining same)

If earth suddenly contracts to 0.5 times of its present radius, then the length of the day becomes

If the radius of earth contracts 1/n of its present day value, the length of the day will be approximately