I Calculating Force Needed to Pull Bungee Taught

[sophiecentaur]

some sort of outdoor art exhibition

Haha - right. So it would require "some sort of" qualified Engineer to design a safe version, particularly if the general public would be exposed to it. I think it may be legal to expose oneself to high risks but . . . .

The Energy stored in stretched lines can be dangerously high and the bungier the line, the more Energy is stored. It scares me.

 

[bob012345]

Haha - right. So it would require "some sort of" qualified Engineer to design a safe version, particularly if the general public would be exposed to it. I think it may be legal to expose oneself to high risks but . . . .

The Energy stored in stretched lines can be dangerously high and the bungier the line, the more Energy is stored. It scares me.

I wonder if it might be possible to make the line out of colored paper, the kind of strips for party decorations?

 

[sophiecentaur]

I wonder if it might be possible to make the line out of colored paper, the kind of strips for party decorations?

A short length could self-support but any wind would tear it. Then here's the problem of rain . . . . . .

The best thing (for a much shorter installation) would actually be steel wire. Minimal stretch so less sag and less stored Energy.

 

[DaveC426913]

The Energy stored in stretched lines can be dangerously high and the bungier the line, the more Energy is stored. It scares me.

The more I think about it, the more I concur. There's almost no way to do this that doesn't involve a dangerous amount of stored energy. That should not be understated.

 

[fascinated]

Thanks again for all the replies.

If it is held at anything other than vertical, it will get closer and closer to a straight line, but never achieve it.

Yep, got that.

You could use an almost invisible thin cord in a catenary to uphold a more visible cord in a straight line like a suspension bridge.
View attachment 290058

This! It was brought up before as I couldn't see how this gets done. With the spectra braid line, we have the sag down to 2.5 feet. This would allow us to hang the first line at 12.5 feet and have a perfect line at 10 feet.

My question again is, what can be used for the bottom line? If it is just another "more visible" line, how could it ever form a horizontal line without nearly infinite vertical supports? Or am I totally missing this one too?

Thanks again

Please don't try this. When this wire breaks it turns into an unpredictable flying Ginsu knife that could maim or kill someone.

BoB

Lol... at least when the bungee snaps, it goes almost perfectly straight to where it broke.

The picture of a rubber band is a complete red herring but you could measure a finite sag in it, using interferometry.

I got you on everything else, but this one is still tough. I *almost* think that's true.

I suspect it is some sort of outdoor art exhibition/festival probably in a large field.

Private land owner... but who knows.

 

[fascinated]

Haha - right. So it would require "some sort of" qualified Engineer to design a safe version, particularly if the general public would be exposed to it. I think it may be legal to expose oneself to high risks but . . . .

The Energy stored in stretched lines can be dangerously high and the bungier the line, the more Energy is stored. It scares me.

It's impossible. We have to do it a different way.

The more I think about it, the more I concur. There's almost no way to do this that doesn't involve a dangerous amount of stored energy. That should not be understated.

I think the supported, more visible line would work, if that is possible. I still don't see how we guarantee a horizontal line.

Thanks again, folks.

 

[DaveC426913]

I think the supported, more visible line would work, if that is possible. I still don't see how we guarantee a horizontal line.

It won't. All it will do is make more (granted, shorter less saggy) caternaries.

 

[jbriggs444]

5000 feet of helium-filled tube constructed of aluminized Mylar and deployed on a dead calm day?

 

[pbuk]

High voltage electricity pylons are generally about 1,000 ft apart. You want something 5 times further apart. Forget it.

 

[berkeman]

Thread closed for Moderation...

 

[berkeman]

I wanted to keep going, but the wife got scared. We were next to a highway.

Please don't try this. When this wire breaks it turns into an unpredictable flying Ginsu knife that could maim or kill someone.

Private land owner... but who knows.

Okay, this has gone on long enough. There have been several reports of safety concerns in this thread, and not knowing the actual application prevents us from proposing safer alternatives. Thread will remain closed.

@fascinated -- if you need a long straight line, the laser is the way to go. Please keep laser safety considerations in mind, though, to ensure that nobody is exposed to laser light at any level that can cause eye damage.