Time period of a heavy spring with an attached mass at the end

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Discussion Overview

The discussion revolves around deriving the time period equation for a spring-mass system that accounts for the mass of the spring, specifically seeking a method that does not rely on energy analysis. Participants explore the implications of including the spring's mass in the derivation while maintaining a focus on the mechanics similar to those used for a massless spring.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant seeks a derivation method for the time period of a spring-mass system that includes the mass of the spring without using energy analysis.
  • Another participant questions the assumptions regarding the distribution of mass along the spring's length, specifically asking if it is uniformly distributed.
  • A participant confirms that they are assuming a uniformly distributed mass along the spring.
  • A participant mentions finding resources that use energy analysis, which does not meet the original request for a different approach.
  • Another participant notes that the equations of motion for a spring without an extra mass are similar to the wave equations for longitudinal waves, indicating that the mass at the end alters the boundary conditions.
  • It is mentioned that there are approximate solutions that include a factor of m/3, where m is the mass of the spring, but the justification for this factor is not provided in the referenced material.

Areas of Agreement / Disagreement

Participants have not reached a consensus on a specific method for deriving the time period equation without energy analysis. There are differing views on the assumptions regarding mass distribution and the applicability of existing resources.

Contextual Notes

The discussion highlights limitations related to the assumptions about mass distribution and the reliance on existing derivations that may not align with the requested approach. The justification for certain approximations remains unresolved.

thephysicist
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I want to know the way to derive the time period equation of a spring mass system accounting for the mass of the spring but not using the energy analysis method but by proceeding in the same way as we do by ignoring the mass of the spring. Please help. I did not find any texts at my level. Any links would suffice gratefully.
 
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What assumptions are you making about the distribution of mass along the length of the spring?
 
Uniformly distributed.
 
thephysicist said:
I want to know the way to derive the time period equation of a spring mass system accounting for the mass of the spring but not using the energy analysis method but by proceeding in the same way as we do by ignoring the mass of the spring. Please help. I did not find any texts at my level. Any links would suffice gratefully.

I did a Google search on "mass on heavy spring" and found loads of hits. I am not sure what your level is but how does this link suit you (it was top of my list)?
 
Thanks for the link but this derivation also uses energy analysis. I want to find an approach that is similar to deriving the equation of motion of a massless spring with an attached mass.
 
The equations of motion for the spring without an extra mass on the end are basically the same derivation as the wave equations for longitudinal waves (not transverse waves in a string under tension).

The mass on the end just changes the boundary conditions at the end.

You will find plenty of references to an approximate solution that includes m/3, where m is the mass of the spring. The approximations is to assumes the spring mass is small enough not to affect the vibrating shape of the spring. That seems to be what sophiecentaur's reference is doing, but it just states the m/3 factor without attempting to justify it.
 

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