Question of a problem on Poynting vector

1. Dec 5, 2008

yungman

I have been working on this problem and I cannot get the solution as shown in the book. I scan the question and solution of the book and my work. It is too difficult for me to type it in, please open the attach scanned pdf file. THe top part is the copy of the book, the lower part is my work. You can see the solution on my part does not agree with the book and I check over my work many times already. Please tell me what did I do wrong
Thanks

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2. Dec 5, 2008

gabbagabbahey

We can't see your attachment until it is approved by admin. It would be quicker if you uploaded your pdf to imageshack.us and then posted a link to it.

3. Dec 5, 2008

yungman

It can be opened now.
Thanks

4. Dec 5, 2008

gabbagabbahey

Not by me it can't. It still says that it is pending approval.

5. Dec 5, 2008

yungman

I just opened already!! I wonder why!!

6. Dec 5, 2008

gabbagabbahey

You can open it before it has been approved since you are the one that attached it. Everyone else has to wait 'til its approved.

Again, you can save a lot of time by uploading it to a free imagehosting site and then just posting a link to it.

7. Dec 9, 2008

Defennder

I don't think your expression for the real part of $$\mathbf{E}(R,\theta,t)$$ and $$\mathbf{H}(R,\theta,t)$$ are correct. Remember that the original phasor expression for E and H has 'j' inside, meaning that you have to multiply throughout by j, so that makes the formerly imaginary part real and the formerly real part imaginary.

8. Dec 9, 2008

yungman

Thanks again. It is so obvious that I just miss it all together. "j" translate to e to the power j(pi/2) which change the cos() to -sin().

Thanks again.