<font color="yellow">ok, then lets say the planet it 4,000,000,000 newtons.</font><br /><br />It can't be measured in newtons, because the acceleration due to gravity varies within it. You must decide on the mass.<br /><br /><font color="yellow">What is the force of gravity in the planet.</font><br /><br />Depends on a few things, the mass of the object that is not the planet, this object's radius from earth's center of mass, the mass of earth within the sphere of that radial distance.<br /><br /><font color="yellow">How would you get the acceleration?</font><br /><br />You would get acceleration due to gravity by dividing the gravitational force by the mass of the small object. The gravitational force is proportional to the mass of the small object, in the equation:<br /><br />gravitational force=Gravitational Constant * Mass of Earth within the Radial Distance * Mass of the smaller object / Radial Distance^2<br /><br />Which can be written simply as:<br /><br />gravitational force=(G*M*m)/(r^2)=m*a<br /><br /><font color="yellow">And, what is the acceleration refering to? Accleration of gravity?? Accleration of what?</font><br /><br />The acceleration that would occur in freefall. Since something inside the earth is not likely to be in freefall, you would have to consider all the forces involved.