Question

In a vacuum, two particles have charges of q1 and q2, where q1 = +3.78 μC. They are separated by a distance of 0.214 m, and particle 1 experiences an attractive force of 3.36 N. What is the magnitude of q2?

Answer 1

Don't forget F=kqQ/r^2. We have everything--distance, force, one charge, and the proportionality constant k. Plugging in and solving for the other charge q (with a bit of algebra) shouldn't be too hard.

Answer 2

I am confused about which q (or Q) stands for what

Answer 3

The letters Q and q are just a labels for the electric charge of two objects. It is just a reminder for us as to where in the equation you need to insert the value for the charges when trying to solve a question. So in this context \[Q=q1\] and \[q=q2\] or \[Q=q2\] and \[q=q1\] i.e. It does not matter which order you put them in, the answer will be the same.