Question

If the diameter and mass of the earth become two times of their present value then the weight of the object on the surface of the earth will be :

Answer 1

Okay we know that weight of an object = mg (Mass of the object x Acceleration due to gravity)

Okay now we know that accleration due to gravity (g) is given by:

g= GM/(R^2) (Let this be the first equation)

Where G is the gravitational constant

M is the mass of the Planet

R is the radius of the planet

Now changing the first equation we get

g= 4GM/(D^2)

where D is the diameter of the planet (R=D/2)