What factor affects the rate of exponential decay in coupled pendulums?

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Discussion Overview

The discussion revolves around the factors affecting the rate of exponential decay in coupled pendulums, particularly focusing on a scenario where one pendulum has a larger mass than the other. Participants explore the dynamics of energy transfer between the pendulums and the implications for decay rates, including experimental observations and theoretical considerations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes a setup with two pendulums of different masses and questions why the rate of exponential decay of the larger pendulum is slower than expected when coupled with a smaller pendulum.
  • Another participant challenges the initial claim by asking for the source of the information regarding the decay rates, implying a need for experimental validation.
  • A third participant clarifies their experimental setup, providing details about the weights and string configuration, seeking confirmation of their description.
  • One participant suggests that friction plays a significant role, proposing that the coupled pendulums experience less friction than a single pendulum, which could account for the observed slower decay rate.

Areas of Agreement / Disagreement

Participants express differing views on the factors influencing the decay rate, with some proposing friction as a key element while others question the initial observations and seek further clarification. No consensus is reached regarding the underlying reasons for the decay rates.

Contextual Notes

Participants mention experimental results and specific setups, but there are unresolved aspects regarding the assumptions made about energy transfer and friction. The discussion does not clarify the mathematical modeling of the decay rates.

Who May Find This Useful

Individuals interested in the dynamics of coupled oscillators, experimental physics, and the effects of mass and friction on pendulum motion may find this discussion relevant.

xlyndseyx
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You have 2 pendulums attached to the same piece of horizontal string.
One pendulum has a large mass, the other is small.
They are both of the same length.
The large pendulum is released from an amplitude and so the small pendulum resonates.
The rate of exponential decay of the large pendulum is much slower, than if it were a single pendulum connected to nothing else.
How and Why is this so?
Surely the rate of exponential decay of the large pendulum should be faster and the pendulum dampened, as when energy is transferred to the small mass pendulum, some is lost from the system as it is converted to heat?

HELP!
 
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The rate of exponential decay of the large pendulum is much slower, than if it were a single pendulum connected to nothing else.
From whence does this info come? Did you do an experiment?
 
This is very interesting. Allow me to venture clarification of the setup: A 1 foot string is tacked to the end of my desk. At the end of that string I place a 1 ounce weight. At the middle of the string I place a 1/2 ounce weight.
I hold onto the 1 ounce weight and taughtly raise the string structure horizontally to the edge of my desk.
Then I let go and observe the motion of the weights as they swing down and pendulum.
Is this a fair description?
 
Yes they're experiment results, which had me puzzled for a while!
But then i figured...FRICTION!
the pendulums which were in resonance had less friction than the single pendulum on its own, therefore the systematic error was reduced and the rate exponential decay was less.
Thanks for the replys though!
 

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