Final answer:
The magnitude of the electric force on object A is 1.62 x 10^-3 N, while the magnitude of the electric force on object B can be calculated using the same formula, substituting the values for the charges and the distance between them.
Step-by-step explanation:
The magnitude of the electric force between two charged objects is given by Coulomb's law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. For object A, which has a charge of +12nC and is at the origin, the magnitude of the electric force on object A can be calculated by considering the charge of object B and the distance between them. Using Coulomb's law, we have:
F = k * (|q1 * q2| / r^2)
where F is the force, k is the electrostatic constant (9 x 10^9 Nm^2/C^2), q1 and q2 are the charges (+12nC and -30nC respectively), and r is the distance between the charges.
Substituting in the values, we get:
F = (9 x 10^9 Nm^2/C^2) * ((12 x 10^-9 C) * (30 x 10^-9 C) / (0.02m)^2)
= (9 x 10^9 Nm^2/C^2) * (0.36 x 10^-18 C^2 / (0.02m)^2)
= 1.62 x 10^-3 N
Therefore, the magnitude of the electric force on object A is 1.62 x 10^-3 N. For object B, the magnitude of the electric force can be calculated using the same formula, substituting in the values for the charges and the distance between them.