If the mass of a planet is 10% less than that of the earth and radius 20% greater than that of the earth then acceleration due to gravity on the planet will be

Question

i need percentage 

Answer 1

Force due to gravity at earth's surface on a mass m:

 

F = GMm/R²

• F = Gravitational Force
• G = Gravitational Constant
• M = Earth's Mass
• m = mass of body
• R = Earth's radius

 

The acceleration is F/m:

 

g = F/m = GM/R²

 

For a planet with 0.9M and 1.2R:

 

a = G(0.9M)/(1.2R)² = 0.625 (GM/R²) = 0.625g   (62.5% of Earth's acceleration due to gravity)