Question

The diagram shows the electric field lines surrounding three electric charges.
Assume that q₁ + q₂ = -2.36

Answer 1

|Fe|= (k*|q1|*|q2|)/r^2
|E|=(k*|Q|)/r^2

k = 8.99*10^9 (N*m^2)/C^2
Fe = Electrostatic force between a pair of charges
r = charge separation
q1, q2 = charge magnitudes
E = electric field
Q = charged object

Have you learned Gauss's Law/Maxwell's first equation yet? This problem is essentially that. It involves the fact that electric field lines begin on positive charges, and end on negative charges. So the number of electric field lines around a certain charge distribution is proportional to the net amount of charge in that distribution. If you look at the diagram, you have twice as many field lines entering q2 as you have leaving q1 and q3. Using that, what can you determine about the signs and magnitudes of the charges?