If the radius of the earth contracts to half of its present value without change in its mass, what will be the new duration of the day?

Options

A. 6 hours
B. 12 hours
C. 18 hours
D. 24 hours

Answer

A

Explanation

`m omega R^(2)`= constant
`rArr omega prop (1)/(R^(2)) rArr T prop R^(2)`
`(T_(1))/(T_(2)) = ((R)/(R//2))^(2)= 4`
`rArr T_(2)= (24)/(4)`= 6 hrs