If the radius of earth is reduced to three-fourth of its present value without change in its mass then value of duration of the day of earth will be _______ hours 30 minutes. [2024]
(13) By angular momentum conservation, I1ω1=I2ω2
25mr2·ω=25m34r2·ω'⇒ω'=169ω
2πT'=169×2πT⇒T'=9T16=916×24hours=9×32hours
⇒T'=272hr=13 hr 30 mins