In a hypothetical situation, the density of earth becomes three times that of its original density, but its radius remains same. The acceleration due to gravity becomes : (take `g = 10 m//s^(2)` on the earth)

Options

A. `20 m//s^(2)`
B. `40 m//s^(2)`
C. `30 m//s^(2)`
D. `10 m//s^(2)`

Answer

C

Explanation

As `g = (GM)/(R^(2)) = (G.(4)/(3) pi R^(3) rho)/(R^(2)) = (4)/(3) pi G rho R`
if density is made thrice, then g will also become 3 times, i.e., `10 xx 3 = 30 m//s^(2)`