# Homework Help: Really weird one

1. Feb 11, 2008

### eagleswings

[SOLVED] really weird one

1. The problem statement, all variables and given/known data A small sphere that carries a charge q is whirled in a circle at the end of an insulating string. the angular frequencyy of rotation is omega [w]. What average current does this rotating charge represent?

2. Relevant equations I = dQ/dt; w = 2(pi)/T; x[t] = Acos[wt +C];

3. The attempt at a solution; this question doesnt make sense to me. q never changes - it just travels in a circle - so dq/dt =0;there is one charge going in a circle, but not axially which would represent charge in a conduit. is this a picture of alternating current? [we haven't gotten to that yet].

2. Feb 12, 2008

### Shooting Star

Current is the net charge per unit time passing a given point. On any point on the circumference, what is that value?

3. Feb 13, 2008

### eagleswings

That would be qw = charge per second. surely not that simple. thanks

4. Feb 14, 2008

### Shooting Star

Should be q/T = qw/2pi.

5. Feb 24, 2008

### eagleswings

thanks shooting star!