Just pointing out something said awhile ago. The size of a planet isn't what determines the force of its gravity. The force of gravity is determined by a planet's mass, not it's size. King Kai's planet can be tiny but still have 10x the mass. It would just be really dense. Totally possible though. For example, a black hole, something people have brought up a lot in this little discussion, takes up literally no space but has a huge mass. So, what I'm trying to say is that Planet Vegeta was more than 10x as massive as Earth, it just wasn't necessarily 10x as big.