Question

if the radius of earth becomes n times its present value without cjange in mass then duration of the day become

Answer 1

according to 3rd law of Kepler

time^2=radius^3

so if radius becomes n times... then Time will become n^.3/2

Answer 2

As per the momentum of earth = I * W

Here moment of inertia is I then M * R^2 and its angular velocity is W

The radius of the earth will become n times which means that I will be n^2.

Hence the angular velocity will become (1/n^) times of the conserved momentum.

Hence day duration will become 24 * n^2 hours.