The lines show the equipotential contours in the plane of three point charges, Q1, Q2, and Q3. The values of the potentials are in kV as indicated for the +5, 0, and -5 kV contours. The positions of the charges are indicated by the dots.
the work required to move a charge of -0.51×10-12C from i to b is 3.06×10-9 J
a: Calculate the size of the electric field at k.
b: Calculate the size of the force on a charge of 8.00×10-19 C at g.
c: Calculate the size of Q3. The magnitudes of the three charges are in the exact ratios of 1 to 2 to 3.