In part (a) of the figure, particle 1 (of charge q1) and particle 2 (of charge q2) are fixed in place on an x axis, 12.00 cm apart. Particle 3 (of charge q3 = +8.00×10−19 C) is to be placed on the line between particles 1 and 2 so that they produce a net electrostatic force on it. In part (b) of the figure below gives the x component of that force versus the coordinate x at which particle 3 is placed. The scale of the x axis is set by xs = 12.00 cm. What are (a) the sign of charge q1 and (b) the ratio q2/q1? (a) (b)