Hello ,
about the band theory I was confused some how
seeing the attached image I ask :-
1- when the atoms are far away we take a single atom alone as a system , but when atoms get closer we identify them all as the system , right ?!
2- why do we use the word " splitting" , why...
""theta going to zero" would be to merely evaluate along those curves closing in on the x-axis when approaching 0.
""
ok, thank you , this note wasn't in my mind :)
IF another limit turns to be
limit (z) = r cos(2t)sin(t)
r->0
for example , wouldn't this make the limit value =zero , and wouldn't this make it impossible for any other curve to make the limit dependent on another parameter because I didn't choose a certain curve in polar ?! or am I...
Hello
how can I find the moment of inertia of a circular sector about the X axis , which the sector is symmetrical about , with -θ down and θ above ?!
I_{x} = ∫y^{2} dA = ∫y^{2} *y *dx
Or =∫∫ y^{2} dy dx
I don't know how to put the limits of integration , I turned it to polar...
Very interesting!
My initial reaction is that you have found a bug in Wolfram (good feat! )
:)
Thanks a lot all , It's not good to lose confidence in wolfram :)
would they give me a free membership If I send them this mistake ? :D
well actually I do want to get premium , but I...
Hello
I have the limit
lim (x^9 * y) / (x^6 + y^2)^2
(x,y)---> (0,0)
when I use polar the final result is
limit =
lim (r^6 cos^9 (theta) sin (theta) ) / (r^4 cos^6 (theta) + sin^2 (theta))
r--->0
and substituting r = 0 , it will give zero
* I tried it on wolfram...
thank you ,
For some reason I may need to read more about this topic , can you tell me about a good source /book talking about it ?! or some lecture vedio ?furthermore , about what I said about the time varying current , we know that the (B) resulting from a current loop at the centre = u I...
Hello,
Why do we use KVL in Ac circuits ?! or to be more specific is it accurate to use it in Ac circuit , just the same accuracy as using it in Dc ?!
Doesn't the current that pass through the circuit itself make it's own variable magnetic field , which crosses the loop of the circle ...
You mean that the observer will see the front ball first , but also she will see the speed differences so she will not say a thing about simultaneity
But in the light example , she will see the front first , and also she will notice the same speed of light so she will say the events aren't...
hello
About Einestien's train example
I can't get what it really does with the constancy of the speed of light , what would be the difference if , instead of two bolts , we have two balls thrown at the same angle ?!
the observer in the train would still see the front ball first...
Hello,
is the strain defined as the absolute deformation to the initial ? i.e is it always positive ??
If Yes , then poission's ration is negative for compression of ordinary materials ?
I found some answers , but what I can't well understand is
how the pressure difference between the water and the air due to the curviture is multiplies by the (whole area) of the sheet , why ?
Yes I do know that and I wrote that above , I asked what would be (mathematically) the radius curvature if theta was 30 degrees for example
Any way it is not my basic question here :D
HEllo
Can I find a physics reference for these three topics ??
I have Serway but it just mentions elasticity in a short form which is not so good and has no thing about surfacetention - bubbles , what book could have theese topics in an extended form , Just as serway explains motion and...