Re: [Phys-L] Electric Current ... including steady current in a loop

[Robert Cohen <Robert.Cohen@po-box.esu.edu>]

On Friday, February 16, 2018 2:28 PM, Jeffrey Schnick wrote:

> But to say that one part of the flow of something through a closed surface,
> or the flow of something through an open surface, is the rate of change in
> the amount of that something, bothers me; I can live with it though.
> I was hoping I was missing something.

To me, they are two different usages of "dq" that happen to be equal in this case. :)

Just curious -- are you also bothered by figuring out the total mass of a ball by cutting it into
pieces of mass dm and then integrating?  In other words, does the use of "dm" bother you
because there isn't a quantity m that is undergoing change during the integration?