i can conveniently understand what divisive units imply, yet not what multiplicative systems imply.

What I mean is, as soon as I read "$12 :mathrmeggs/carton$", i mentally convert it to, "There are 12 eggs because that each carton". I acquire that.

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But, when I view units like joules * seconds, $:mathrmJ cdot s$, it yes, really bothers me for some reason. I"m not certain what it"s saying. It"s no saying the quantity of joules expended over a details time-frame, otherwise it would be joules/second, wouldn"t it? So, as soon as I read units choose joules * second, I shot to relate it to mine egg-carton analogy, and it comes out prefer this:

"There are 12 eggs because that each mutual of a carton."

It just doesn"t make any kind of sense for me. Is this a difficulty for anyone else? need to this be on math SE? Is this even a valid question or am I just asking why $2 + 2 = 4$?

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edited Dec 22 "14 in ~ 17:44

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Kenton WuKenton Wu
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Seems valid to me...

I think the translate of her example can be that you room doing something v some joules, because that some period of time, and also that the product of the variety of joules and also the variety of seconds has a details value, and the systems would be... Joule-seconds!

I can snapshot the operator that an energy storage basic quoting a price for storing energy. Save on computer $10,000 ext joules$ because that $400 ext seconds$ would cost a certain amount. Storing twin the power for fifty percent the time would use the exact same resources, and cost the same.

The most usual example, that course, is the usage of $ ext kilowatt-hour$ as a unit of energy. In this case, you are using the price of power output. Times the time over i m sorry the calculation exists, to stand for the complete energy.

It has actually been typical for some time to stand for the lot of occupational in a task in $ ext man-hours$. The an ext people you have the right to throw at the project, the sooner it will be done...

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A less obvious unit is the measure of the size of, say, a sailboat, in $ ext knot-seconds$...