# Electric Field/Charge cycle, rotating mass problem

1. Jan 26, 2010

### hbeaton

An infinite line charge l is located along the z axis. A mass m that carries a charge q whose sign is opposite to that of l is in a circular orbit in the xy plane about the line charge. If m = 0.28 kg, q = 1.1 mC, l = 3.3 nC/m, and R = 0.25 m (the radius of the orbit), find the period.

Help!

My apologies for not following the given format in advance, I am assisting someone and have very little physics knowledge of my own. Please treat as a t00l.

Thanks,
-H

Last edited: Jan 26, 2010
2. Jan 27, 2010

### Redbelly98

Staff Emeritus
Hello hbeaton, welcome to Physics Forums.

I'll suggest asking the student the same that we ask in our homework template:

1. What equations are, or might be, relevant here? The key words here are "line charge" and "circular orbit". Find equations that have something to do with those, if necessary look through the textbook. If the person is studying electric charge right now, the circular orbits would be in an earlier chapter of the book.

2. Finding the equations, writing them down and looking at them, can help with the next part: making an attempt to solve the problem. Even saying what you think might be involved in solving it, even if that's wrong, can be helpful in getting started.

Hope that helps to get the ball rolling.