If the ice on the polar caps of the earth melts, how will it affect the duration of the day? Explain.

 Answer: If the ice on the polar caps of the earth melts, the water (changing from ice to water), spreads on the surface of earth towards the equator. Due to this reason, the moment of inertia increases, to conserve angular momentum, the angular speed of earth decreases. i.e I⍵ = constant

or, I 2π/T = constant. It gives T ∝ I.

As moment off inertia increases, the time period increases and hence duration of day increased.