Gravitation Question 3

Question 3 - 2024 (27 Jan Shift 1)

The acceleration due to gravity on the surface of earth is $g$. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be :

(1) $g / 4$

(2) $2 g$

(3) $g / 2$

(4) $4 g$

Show Answer

Answer: (4)

Solution:

$g=\frac{GM}{R^{2}} \Rightarrow g \propto \frac{1}{R^{2}}$

$\frac{g _2}{g _1}=\frac{R _1^{2}}{R _2^{2}}$

$g _2=4 g _1\left(R _2=\frac{R _1}{2}\right)$