Question

The force acting between two charged particles A and B is 5.2 × 10-5 newtons. Charges A and B are 2.4 × 10-2 meters apart. If the charge on particle A is 7.2 × 10-8 coulombs, what is the charge of particle B?

Answer 1

F = k(q1)(q2) / r^2
where F = force, k is coulomb's constant k = 8.99 x 10^9 N m^2 / C^2, q1 and q2 are your charges, and r is the radius (distance between the two particles, in this case). plug in particle A's charge as q1, and solve for q2