Angular Momentum Equations

  • Thread starter jg370
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Homework Statement


In my study of Quantum Mechanics, I am using Introduction to Quantum Mechanics by David J. Griffiths. So far I have done quite well. However, as I come to the section on Angular Momentum, I need help to get further.

Homework Equations


Classically, the angular momentum of a particle is given by:

[tex] \mathbf{L = r\times p }[/tex]

This is all good. But this is followed by component form of the above equation as:

[tex] L_x = yp_z-zp_y, L_y = zp_x-xp_z, L_z = xp_y-yp_z[/tex]

I am curious how [tex] L_x, L_y , L_x[/tex] are mathematically derived

The Attempt at a Solution



I have look at other textbooks and various posting on internet but I have not been able to find anything to help me with. Hopefully, someone will suggest some thing.

Thanks
 

Answers and Replies

  • #2
D H
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Let [itex]\mathbf r = x\hat x + y\hat y + z \hat z[/itex] and [ltex]\mathbf p = p_x \hat x + p_y \hat y + p_z \hat z[/itex]. What ls [itex]\mathbf L = \mathbf r \times \mathbf p[/itex]?
 
  • #3
ideasrule
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By the way, that definition is just part of classical mechanics. It's not unique to quantum mechanics.
 

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