The speed of earth's rotation about its axis is `omega`. Its speed is increased to `x` times to make the effective acceleration due to gravity equal to zero at the equator, then `x` is around `(g= 10 ms^(-2) R = 6400 km)`

Options

A. 1
B. 8.5
C. 17
D. 34

Answer

C

Explanation

`omega=(2pi)/T=(2pi)/(24xx60xx60)` rad//s
Now, `g.=g-(omega.)^2R`
`rArromega.=sqrt(g/(R_e))=1/800` (at equator `lamda=0`)
`omega/(omega.)=(2pi)/(24xx60xx60)xx800,omega.=17omega`