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i'm doing this problem with charge and current in a wire and am having a bit of difficulty in the final part of the problem.

A total amount of charge (C) that enters a wire is given by Q = 4t - t^2, where t is greater than or equal to zero and in seconds.

A) graph this equation, t interval 0->4

B) Find current expression in terms of time

C) graph this, t interval 0->4

D) explain why I has value at t=2s that is observed.

I've done A-C already. I know that I = dQ/dt, took the derivative and graphed both equations for the given intervals. I know that at t=2s, the current is 0A. My question is, why is this?

I figure that it's due to the fact that at this point in time, the wire has the maximum amount of charge entering it that it can handle and then the current starts flowing the opposite direction. I think it possibly has roots in conductivity/resitivity, though I'm not fully sure.

Any help in the right direction would be much appreciated

thanks

-twiztidmxcn

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# Homework Help: Charge and current in a wire

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