What is the magnitude of the Coulomb force between a charge of +0.60 C which is separated by 3.0 m from a second charge of -0.20 C and isolated/shielded from all other charges? Answer in N, using scientific notation (4123N = 4.123E+3 and 0.5678N = 5.678E-1), with a positive answer meaning a repulsive force and a negative answer meaning an attractive force.