If the radius of the earth is suddenly halved keeping its mass constant find its time period of rotation around its own axis

Explanation

When the radius of the earth gets reduced suddenly keeping its mass constant, the angular momentum of the earth constant.
`Iomega` =constant
`(2)/(5)MR^(2)xx(2pi)/(T)` constant t
since mass .M. is constant `:.R^(2)alphaT`
The radius changes form R to R/2.
`(R^(2))/(((R^(2))/(4)))=(24"hour")/(T)" ":.T=6` hour