Question

What would be the value of g on the surface of the earth if it's mass was twice and it's radius half of what it is now?

Answer 1

As we Know the formula :

g= GM/R²----------------(1)

where g is acceleration due to gravity

M is mass of the earth

R is radius of earth

G is universal gravitational constant.

If mass is twice =2M

RADIUS is half= R/2

let g1 be the new gravity .

Substituting in formula (1) we get.

g1= Gx2M/(R/2)²

g1=8 (GM/R²)

g1= 8xg

So the new gravity would be 8 times of original value that is 9.8 m/s².

Hence g1=78.4m/