If radius of the earth contracts to half of its present value without change in its mass, what will be the new duration of the day?

Explanation

`W=(1//2) I(omega_(1)^(2)-omega_(2)^(2)) =(1//2)(2//5) mR^(2)[(2pi//T_(1))^(2) -(2pi//T_(2))^(2)]=9.36 xx 10^(28) J`