Posted by piyar on Monday, April 30, 2012 at 3:41am.
two planets of mass "m" and "M" respectively. Have centre to centre seperation of "R" . At what distance from the centre of the planet of mass "M" do the gravitational force of planets cancel each other??????? plz urgent help me?

physics  Elena, Monday, April 30, 2012 at 1:41pm
G•m(o)•M/x^2 = G•m(o)•m/(Rx)^2,
m/M = (Rx)^2/x^2,
Since all numbers are positive,
sqrt(m/M) = (R/x) 1.
x = R/[1 +sqrt(m/M)]