Question

If earth suddenly contracts such that its radius becomes one third of radius of gyration. How much will decrease the duration of the day now? Suppose that the mass of earth remains unchanged.

Answer 1

According the law of conservation of angular momentum,

L₁ = L₂

or I₁ω₁ = I₂ω₂ ..........(1)

∴ Decrease in duration of days,

∆T = T₁ - T₂ = 24hr - 2 hr. 40 min

= 21 hr 20 min