Any mathematics gurus that can figure a real world problem?.

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Kevin Johnson
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Re: Any mathematics gurus that can figure a real world problem?.

Post by Kevin Johnson » Fri Oct 19, 2018 10:37 am

Interested readers can investigate the internal friction damping characteristics of elastic ropes through a number of approaches. The most research in this specific aspect, understandably, appears to have been done by the military with respect to mooring lines.

This Google search generates many full text publications without a paywall:

https://www.google.com/search?q=hystere ... e&ie=UTF-8

https://www.physicsclassroom.com/mmedia/energy/pe.cfm

The representation of the pendulum above using two forces (gravity and tension) neglects the third force of internal friction. This third force would also be set against the efforts of the swing rider in cyclically raising their center of mass to increase their potential energy.

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Re: Any mathematics gurus that can figure a real world problem?.

Post by Kevin Johnson » Sat Oct 20, 2018 8:04 pm

Just an aside: I remember chains being used for swing sets.
... so that I could really swing hard and achieve a brief free-fall followed by a jerk on the chains at the peaks of the swing path,...
It looks like some modern sets have protective sleeves over chains.

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Re: Any mathematics gurus that can figure a real world problem?.

Post by Greenlight » Thu Oct 25, 2018 12:13 am

If you look at the equation for "period"/time, you will note the "L" (rope length) in the numerator of the square root function. As "L" increases, "T" (time) increases.


Aerodynamics will play a small role, but almost insignificant when compared to the gravitational force. If you replaced the human on the swing with something as large (cross section area), but very light (feather) aerodynamics would play a huge role.
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Re: Any mathematics gurus that can figure a real world problem?.

Post by midnightbluS10 » Sun Nov 11, 2018 12:54 am

Kevin Johnson wrote:
Sat Oct 20, 2018 8:04 pm
Just an aside: I remember chains being used for swing sets.
... so that I could really swing hard and achieve a brief free-fall followed by a jerk on the chains at the peaks of the swing path,...
It looks like some modern sets have protective sleeves over chains.
As a kid, I only remember swingsets having chains. Never anything else. Kids' swing and adult swings alike both used that double linked bowtie-like links.
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Kevin Johnson
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Re: Any mathematics gurus that can figure a real world problem?.

Post by Kevin Johnson » Sun Nov 11, 2018 1:17 am

I remember the ones in a State Park having heavy duty links on a very tall frame with a thick black flexible (rubber?) seat.

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Re: Any mathematics gurus that can figure a real world problem?.

Post by midnightbluS10 » Wed Nov 21, 2018 10:32 am

Kevin Johnson wrote:
Sun Nov 11, 2018 1:17 am
I remember the ones in a State Park having heavy duty links on a very tall frame with a thick black flexible (rubber?) seat.
I remember something similar. In fact, I swear they were made from old tire treads, it seemed like.
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