physics
posted by alex .
trying to study but stuck with this one.
Two tiny spheres have the same mass and carry charges of the same magnitude. The mass of each sphere is 4.62 x 106 kg. The gravitational force that each sphere exerts on the other is balanced by the electric force. Determine the charge magnitude.

F(el)=k•q²/r²
k =9•10^9 N•m²/C²
F(gr) =G•m²/r²
G =6.67•10^11 N•m²/kg²,
k•q²/r² = G•m²/r²,
q =sqrt(G•m²/k)