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Debanjana Adhikari posted an Question
May 24, 2020 • 16:57 pm 30 points
  • CSIR NET
  • Physical Sciences

How do we understand that three components of angular momentum not constant of motion? any short process??

The Lagrangian of a system moving in three dimensions is L=m m( si) + The independent constants of motion is/are (a) energy alone (b) only energy, one component of the linear momentum and one component of the angular momentumn (c) only energy, one component of the linear momentum (d) only energy, one component of the angular momentum

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  • comment-profile-img>
    Dhairya sharma

    when something is missing in Lagrangian like x or thitha then corresponding momentum is conserved and it's called cyclic coordinate

  • comment-profile-img>
    Chandra prakash best-answer

    for simple explanation of this type of prob ...see attached file dear....

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    I hope you got it my point dear

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    no need calculation.. just memorise some fact and solve quickly... best regards

  • comment-profile-img>
    Ruby negi

    you know there is no need to do calculation in this question, see here is no cyclic coordinate so no linear momentum is conserved, and lagrangian is independent of time so only energy is conserved....

  • comment-profile-img>
    Ruby negi

    here is the solution...

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    I did calculation only for explaination.. otherwise here is no need of calculation..

  • comment-profile-img>
    Dhairya sharma

    if T means time is not present in Lagrangian then it's symmetric in time . and symmetry in time leads to conservation of energy.

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