Question

If the radius of earth shrinks by 1.5 % ( mass remaining same ), then the value of gravitational acceleration changes by

• A. 2 %
• B. -2 %
• C. 3 %
• D. -3 %

Answer 1

The correct option is C 3 %

g = G M / R²

as, R is decreased by 1.5%

So, new Radius , R' = R - 0.015 R = 0.985R

So, new g, g' = G M / (0.985R) ²

= 1.0306 G M/ R²

So, change = 0.0306

% change = 3 % (approx)