1.5 LTC reward for equations needed and help with first year physics work

[newuser20]

http://imgur.com/ZyiokLn

This is the problem,

I need the equations to calculate the problems, and then some feedback on if its right. 2 LTC reward if this is done tonight

[newuser20]

Bonus for clarity

[Sgt.Hartman]

Ok let me try the first one:

a) H_x = E_y/Z_F0 (only got x-component of magnetic field)

b) P = |E|²/2*Z_F0

c) S_z = E_y x H_x = -E_y*H_x (Poynting points into z-direction)

Am I right? (has been toooo long) 

[newuser20]

For the first I used  V x E = -dB/dt

to get:

KE_o sin (wt-kx+psi) = -DB/dt

B = kE_o/w * cos(wt-kx+psi) * i hat

I'm not sure this is right or what the Zfo was in your solution.

b) 1/2 epsilon_o E^2


C)

k*(E_o)^2/W cos^2(wt-kx+psi) * 1/u_o

can you check what you wrote was the same ?

[Sgt.Hartman]

I didnt quite get what you elaborated...

a) I meant Z_F0 is free space impedance 377 ohms. If you have the E-field given, then also H-field ist given via Z_F0

b) U use a formular for static fields. But as far as I see we have a constant frequency continuous wave travelling in free space. Since its sin-wave we have to get average rms value that is expressed with 1/2

c) Definition of poynting vector is: S = E x H whereas all components are 3d vectors.

[newuser20]

let me start with saying I've missed a few lectures so im learning this online.


http://en.wikipedia.org/wiki/Magnetic_field

First part under 'Maxwell's equations' section
V being the triangle thing, which i take to mean d/dx+d/dy+d/dz

Which gives you a result in the i direction, nothing in j,k (y,z).

Honestly ive never seen Z before, do you mind showing me the equations you used ?

C)
This is just the cross product of the perpendicular electric and magnetic fields and is correct  ?

[newuser20]

next part:

Ok so for the next part the parity of the box confuses me
the equation of motion is psi(x) = Ceax + De-ax
Ce-aL = Bsin(-kL) DeaL = Bsin(kL) For odd function C = -D
even solution is similar with C = D
But what does this mean ?
To find the energy You use the eq E psi(x) = -h/2m d2psi(x)/dx2 + V(x) Psi(x)
Diff twice and plug in etc ?
c) will post later

[Sgt.Hartman]

let me start with saying I've missed a few lectures so im learning this online.


http://en.wikipedia.org/wiki/Magnetic_field

First part under 'Maxwell's equations' section
V being the triangle thing, which i take to mean d/dx+d/dy+d/dz

Which gives you a result in the i direction, nothing in j,k (y,z).

Honestly ive never seen Z before, do you mind showing me the equations you used ?

C)
This is just the cross product of the perpendicular electric and magnetic fields and is correct  ?

http://en.wikipedia.org/wiki/Impedance_of_free_space
Section plane wave solution. We have time continuous fields. That simplify maxwells equations a lot.

ad c) Yes but consider peak value and rms value. It depends what you have, then you have to add 1/2 or not.

Do you have a solution somewhere???

Second part let me take a look into my cryst... eeeeh books