- #1
stunner5000pt
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- 2
Homework Statement
Wangsness Exercise 24-6
A particle of charge q and mass m is traveling with a velcoity u i nthe field of a plane EM wave in free space that itself is traveling in the z direction.
Find the force on the particle.
What does this become for the special case in whic hthe particle is traveling in the same direction as teh wave?
What is the direction of the force?
Under what circumstances (if any) will the force vanish in this case??
2. The attempt at a solution
First of all I am stumped as how to find the force. Would i just simply use the lorentz force law??
If that is the case then
Suppose we assume the E to point in teh X direction and the B to point in teh Y direction then
[tex] \vec{F} = q (\vec{E} + \vec{u} \times \vec{B}) [/tex]
suppose the particle was traveling in teh Z direction then
[tex] \vec{F} = q (\vec{E} + u\hat{z} \times B\hat{y} ) [/tex]
[tex] \vec{F} = q (\vec{E} + uB (-\hat{x})) [/tex]
the force is pointing the x direction
The magnetic force would vanish if V is parallel to B
but the electric force will never vanish
is this even clseo to being right? OR am i sorely mistaken?
Thanks for your input!