Energy question, what are the quantities conserved?

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SUMMARY

The discussion centers on the conservation laws applicable to a particle's motion along the x and y axes. The participant initially questions the conservation of momentum and angular momentum due to the presence of external forces and torques. However, they conclude that energy is conserved in both the x and y directions, which allows them to derive the numerical answer for their homework problem. The equations of motion, specifically ##\ddot x## and ##\ddot y##, indicate that energy conservation applies in this context.

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Clara Chung
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Homework Statement


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Homework Equations

The Attempt at a Solution


I don't know how to do the last part. What are the additional conservation laws? I don't think momentum is conserved because there is force acting on the particle. I don't think angular momentum is conserved too because there is a torque acting on the particle.
Here is the numerical answer:
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Note that the equation for ##\ddot x## involves only ##x## (not ##y##). Similar comment for ##\ddot y##.

Imagine the x equation described a particle moving only along the x-axis. Anything conserved in this x-motion?
 
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TSny said:
Note that the equation for ##\ddot x## involves only ##x## (not ##y##). Similar comment for ##\ddot y##.

Imagine the x equation described a particle moving only along the x-axis. Anything conserved in this x-motion?
Thank you, I think the energy along x and y-axis are conserved too. Then I can find the answer.
 

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