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

Tech questions that don't fit above forums

Moderator: Team

Kevin Johnson
HotPass
HotPass
Posts: 9365
Joined: Tue Nov 22, 2005 5:41 am
Location:

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

Post by Kevin Johnson »

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.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
Kevin Johnson
HotPass
HotPass
Posts: 9365
Joined: Tue Nov 22, 2005 5:41 am
Location:

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

Post by Kevin Johnson »

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.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
Greenlight
Pro
Pro
Posts: 415
Joined: Wed Feb 16, 2005 10:37 pm
Location:

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

Post by Greenlight »

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.
Project Greenlight
User avatar
midnightbluS10
Expert
Expert
Posts: 933
Joined: Sun Oct 20, 2013 8:41 am
Location: Shreveport, LA

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

Post by midnightbluS10 »

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.
JC -

bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
Kevin Johnson
HotPass
HotPass
Posts: 9365
Joined: Tue Nov 22, 2005 5:41 am
Location:

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

Post by Kevin Johnson »

I remember the ones in a State Park having heavy duty links on a very tall frame with a thick black flexible (rubber?) seat.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
User avatar
midnightbluS10
Expert
Expert
Posts: 933
Joined: Sun Oct 20, 2013 8:41 am
Location: Shreveport, LA

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

Post by midnightbluS10 »

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.
JC -

bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
Post Reply