Calculating the Average Current of a Rotating Charge q | Insulating String

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The discussion revolves around calculating the average current of a rotating charge q on an insulating string. The key point is that while the charge does not change (dq/dt = 0), it still represents a current due to its circular motion. The average current can be derived from the relationship I = q/T, where T is the period of rotation. The equation I = qw/2π is suggested as a way to express the current in terms of angular frequency. The conversation highlights the confusion around the concept of current in this context, ultimately leading to a clearer understanding of the average current for a rotating charge.
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[SOLVED] really weird one

Homework Statement

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?



Homework Equations

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



The Attempt at a Solution

; this question doesn't 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].
 
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Current is the net charge per unit time passing a given point. On any point on the circumference, what is that value?
 
That would be qw = charge per second. surely not that simple. thanks
 
Should be q/T = qw/2pi.
 
thanks shooting star!
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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