Question

If you quadrupled the mass and tripled the radius of a planet, by what factor would gg at its surface change

Answer 1

Answer:

4/3

Explanation:

We already know aforehand that the acceleration due to gravity on the surface of a planet is given as

GM/r²,

Now, if the mass is quadrupled, we would have

G4M/r²,

If the radius is then tripled, we would have again

G4M/3r²

And that is what we have, now, to get the factor that the acceleration changes is simply to compare it with the primary equation

HM/r² = G4M/3r²

And thus, we find out that the factor is 4/3 or 1.333