Question

1 point If the polar ice caps melt due to an increase in global temperatures, more of the Earth's water will be distributed closer to the equator. What would this do to the Earth's moment of intertia? It would not change. The moment of inertia would decrease. O The moment of inertia would increase. 1 point If the polar ice caps melt as in the previous question, what would that do to length of Earth's day? O The length of Earth's day would be unchanged. O The day would be a bit longer. O The day would be a bit shorter.

Answer 1

8. When the ice caps melt at the polar region, the mass will decrease at the polar region as the water goes to the equator region. The mass will be more in the equator region. As the mass is located more away from the axis at which we calculate the moment of inertia, (I = M R²), the moment of inertia increases. Thus as the polar caps melt, the water goes to the equator region and cause the moment of inertia of the earth to increase.

9. According to the conservation of angular momentum,
L = I $\omega$, should be conserved.
As the water mass increases in the equator region, the moment of inertia of the earth increases. In order to conserve the angular momentum, the angular velocity must decrease.
When angular velocity decreases, the days will be longer as it takes more time to complete one rotation