Why does current lag behind voltage in inductor?

[Bassalisk]

what an interesting couple pages.

i'm not anti-math but am sympathetic toward those who struggle with it.

being mildly autistic, my awkwardness made math more difficult for me than it should have been. simple arithmetic mistakes scuttled many a calculus problem that i'd set up correctly but blew the evaluating part from a dropped sign or something.

result is i am real skeptical of formulas unless i can "feel" them.

when you're as dumb as me you have to work twice as hard as normal people and that's why i try to explain things simply - if it keeps somebody from giving up it's worthwhile.

for anybody stuggling with concept behind operator j ;
here's what i decided felt right:
multiplying by operator j shifts phase 90 degrees
multiplying twice shifts you 180 degrees,
which is exactly same as multiplying by -1
so obviously j is sqrt(-1) , for when you multiply it by itself you get -1 and that's a square root.
And of course it's imaginary because everybody knows negative numbers don't have square roots.

works for me. I'm no Euler.
but i learn from most everybody i meet.
great discussion guys , thanks.

old jim

Well you are "dumb" as I am. Because I can only work with formulas if I can "feel" them too. Mathematical and physical ones, both I have to "feel".

 

[psparky]

I'm not sure I have ever needed to "feel" math...just understand it.

To me math has come easy...but I certainly "feel" for those who trouble with it.

In alegebra there is one basic rule..."what you do to one side of the equation...you do to the other side".

That and there are only two things you can do in math...add or multiply.

Subtracting is addition of the opposite...division is multipication of the reciprical.

And yes, there are a ton of little rules, but the above is pretty much the basics...I "feel".

 

[sophiecentaur]

'multiply' is just a series of additions, in any case.
But ordinary arithmetic rules are not used in all maths - so there is a tiny bit more to it.

 

[psparky]

I agree.

You can certainly go far with the basics I mentioned...differetial equations, calc 3 and so on.

But yes...it is a bit more complicated.

And actually the math is simple eventually...learning how to set up the problems in real life...or in story problems is the trick.