Question

what would be the value of 'g' ( gravitational acceleration) on the surface of earth if it's mass was twice as large and it's radius is half what it is how

Answer 1

Concept : Gravitation

Original ‘ g ’ =  GM/R²

According to the question , the mass is twice the original ones and radius is changed to half the original ones .

R = R/2 ,  M = 2M

⇒ g’ =  ( G2M )/(R/2)²

⇒ g’  =  8GM/R²

⇒  g’ =  8g     { GM/R² = g }

Value of g =  8 times the original value of g i.e   8g