Question

When there is a global heating trend on Earth, the atmosphere expands and the length of the day increases very slightly. Explain why the length of a day increases.

Short answer

The decrease in angular velocity of the earth causes the days to grow longer due to global heating.

Step-by-step solution

Concept of law of conservation of angular momentum.

The law of conservation of angular momentum states that there will be no change in the angular momentum unless an external torque acts on the object. Angular momentum of a system is conserved as long as there is no external torque acting on the system.

Reason for causing the days to grow longer.

The expansion of atmosphere causes the moment of inertia of the Earth to increase because the mass goes outward. According to law of conservation of momentum, the angular velocity decreases when there is increase in the moment of inertia. This causes the days to grow longer.