units question


by ehrenfest
Tags: units
ehrenfest
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#1
Aug11-07, 07:18 PM
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If a coulumb is defined as the amount of charge carried by a current of one Ampere in a second, why is its units Amperes seconds and not Amperes per seconds?
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mjsd
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Aug11-07, 07:58 PM
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[tex]I=\frac{dQ}{dt}[/tex] by definition and so [tex]Q = \int I\;dt[/tex] which has a unit of (amperes x seconds)
seems obvious to me, do I understand your question correctly?
ehrenfest
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#3
Aug11-07, 09:01 PM
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Yes, I see how it works mathematically. But I just thought "the amount of charge carried by a current of one Ampere in a second" was similar to the amount of charge carried by a current of one Ampere per second" so it would have units of Amperes/S

mgb_phys
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Aug11-07, 09:10 PM
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units question


No because a coulomb is a total amount of charge not a rate, so after 2 seconds you have 2 coulombs.
mjsd
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#5
Aug12-07, 12:03 AM
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yeah, another example Energy = Power x time
and Energy is not a rate, while Power is. so amount of charge is like "energy" in this analogy


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