Solving for the Magnetic Field & Poynting Vector of an Electromagnetic Wave

[jc09]

If the electromagnetic wave is descirbed as:
E=Eocosw((eu)^1/2z-t)i + Eosinw((eu)^1/2z-t)j
Find the corresponding magnetic field and the poynting vector.

 

[tiny-tim]

Hi jc09!

Show us what you've tried, and where you're stuck, and then we'll know how to help!

 

[jc09]

Well I know VxE= -dB/dt so if i get the curl of E given I will get minus the value of the differentiate form. So will I then integrate back up or is this right?

 

[tiny-tim]

Well I know VxE= -dB/dt so if i get the curl of E given I will get minus the value of the differentiate form. So will I then integrate back up or is this right?

have a del: ∇

s'right!

go for it! ​

 

[jc09]

So I got B=(eu)^1/2Eocosw((eu)^1/2z-t) is that right.
To get the poynting vector I need to use S=E x H. What is H?

 

[tiny-tim]

To get the poynting vector I need to use S=E x H. What is H?

If there's no magnetisable material, then H = B/µ₀ …

$$\frac{1}{\mu_0}\,\bold{B}\ =\ \bold{H}\,+\ \,\bold{M}$$

(see eg https://www.physicsforums.com/library.php?do=view_item&itemid=111 or http://en.wikipedia.org/wiki/Magnetic_field#The_H_field)

 

[jc09]

ok I got it now thanks