Final answer:
To find the charge q, use Coulomb's law and solve for q2, considering that an attractive force implies opposite charges. The magnitude can be calculated by substituting the given values into the rearranged Coulomb's formula and accounting for the known charge, distance, and force.
Step-by-step explanation:
The question asks to find the sign and magnitude of charge q exerting an electrostatic force with another known charge. To solve this, we can use Coulomb's law, which states that the electrostatic force (F) between two point charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. Using the formula F = k * |q1 * q2| / r^2, where k is Coulomb's constant (approximately 8.99 x 10^9 N·m²/C²), q1 is the known charge (+8.44 × 10^-6 C), q2 is the charge we're solving for, r is the separation distance between the charges (0.67 m), and F is the given force (0.961 N).
First, we isolate q2: q2 = F * r^2 / (k * q1). Plugging in the values, we get q2 = (0.961 N * (0.67 m)^2) / (8.99 x 10^9 N·m²/C² * 8.44 x 10^-6 C) to get the magnitude of q. As for the sign, since the force is attractive, the charges must be opposite in sign; thus, q will have negative polarity.