[cripplecreek]

So a rocky planet the size of Jupiter would have the same gravitational pull as a gas giant like Jupiter?

[Junior]

No. A rocky world that size (an impossibility) would be more massive than a gas giant and have a higher surface gravity.

[The_Victor]

So a rocky planet the size of Jupiter would have the same gravitational pull as a gas giant like Jupiter?

No. A rocky planet would have much greater mass that a gas planet of the same size.

[Squawk 8888]

Actually, I don't have the math handy but I believe that a body with the density of rock and the volume of Jupiter would probably be a star, ignited by the pressure of all that mass. That's why rocky planets are small and the only large planets are the gas giants.