Final answer:
To calculate the net force on particle q1, the formula for Coulomb's law (F = k * q1 * q2 / r^2) is used, where k is Coulomb's constant, and the distance r between charges and their magnitudes are taken into account to sum the forces from all other charges.
Step-by-step explanation:
The question involves calculating the net force on a charged particle using Coulomb's law, which states that the electrostatic force (F) between two stationary point charges (q1 and q2) is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance (r) between them. The formula for Coulomb's law is F = k * q1 * q2 / r^2, where k is Coulomb's constant (approximately 8.99 x 10^9 Nm^2/C^2). To calculate the net force on particle q1, we need to find the forces exerted by the other charges and use superposition to sum them, considering both the magnitudes and directions of these forces.
In question 31, the electric field of the +q particle at distance r and the force it exerts on the +2q particle can be determined using principles from electromagnetism and the symmetry of the situation, leading to the conclusion that the electric field would be E/2 and the force would be F/2.