If the density of the earth is doubled keeping its radius constant then acceleration due to gravity will be `(g=9.8 m//s^(2))`

Options

A. `9.8 ms^(-2)`
B. `19.6 ms^(-2)`
C. `4.9 ms^(-2)`
D. `39.2 ms^(-2)`

Answer

B

Explanation

Acceleartion due to gravity `g=4/3 pi p GR`
or `g prop dR [because "density" d=4/3 pi p]`
`therefore (g_(1))/(g_(2))=(d_(1))/(d_(2))`
`rarr (g_(1))/(g_(2))=(d)/(2d)`
`g_(2)=g_(1)xx2=9.8xx2=19.6 ,s^(-2)`