Newtonian physics would say that when you jumped you pushed the elevator away from you (causing more strain on the cables). All the time you are not touching the floor of the elevator, you impart no addition strain on the cables. The cables only have the weight of the elevator on them. When you hit the floor, you again cause additional strain on the cables.
As an example:
Starting position: 500 N on the cable
Jumping up: 700 N on the cable
Off the floor: 300 N on the cable
Landing on the floor: 700 N on the cable
Standing on floor: 500 N on cable

As far as a Water Filled Elevator...since a body is suspended in the water as apposed to rising and falling in air where the vast majority of space including the air is empty due to the low mass of the air....the body sits within and upon the water column directly under it.

Since our bodies will either be suspended within the water or float upon it...there is no ability for the bodies weight to separate itself from the elevators floor.

Split Infinity

 

What in the world are you talking abou?

 

Wait....I apologize for putting it that way....I dont mean to be rude and appreciate your reply.
What I meant to say was....your comments dont address the point do they....
With all due respect....water in an elevator...what?
Why dont we just close this thread....?
Looking at the other physics posts...

 

Wait....I apologize for putting it that way....I dont mean to be rude and appreciate your reply.
What I meant to say was....your comments dont address the point do they....
With all due respect....water in an elevator...what?
Why dont we just close this thread....?
Looking at the other physics posts...

I was addressing this to the issue of Boundries.

In the air filled elevator when a person jumps they can effectively separate their weight from the elevators floor thus remove stress and tension upon the cables.

In the water filled elevator a persons body is suspended in the water and thus cannot separate their bodies weight from the elevator.

Split Infinity

 

Ok....physics men.....or women as the case may be....
Riddle me this...now that you mention it.
Say...I am in elevator and the elevator is decending at the usual rate.
So I have the same velocity as the elevator....I got that.
But then I jump up into the center of the elevator...
When I reach the top of my jump and start to come down ...I'm weightless, right?
So the "boundries" conception is false, right....because at that point in time....I do not add to the elevators weight, right"

This is a completely different situation from your fish in the bucket. The fish are statically placed in their positions, but when you jump, you become a free body, totally disassociated with your container, the elevator. If instead you were statically suspended, there would be an interaction between you and the elevator, which would add all your weight to the whole system.

However, since momentum is conserved and all that, you impart the same force by jumping on the elevator, over time, that you take away during your flight. So, if you average your weight contribution to the elevator over time, it comes out the same as if you just stood there.

 

By the way.....what happens at that moment...when kinetic energy is changed to potential energy?
Being true to the conversation of energy concept....what is given off ...heat...light....what....cause when you change an energy form....somethings got to give....correct

Nothing is given off. One form of energy is converted to another form. Since the two are equal, no other energy is created.

There has to be less kinetic energy than potential energy....does gravity eat the diff up in some way....

Why does there have to be less kinetic energy than potential energy?

Cause when I hit the bottom of the elevator...I would impact with less force than it took to get up to the top of my jump...so where does the energy go....?
Just a thought provoking little snippet.

Why would you impact with less energy than what got you started? You're operating in a conservative system (air resistance and other losses being negligible) You would come down with the same energy you went up with.

 

This is a completely different situation from your fish in the bucket. The fish are statically placed in their positions, but when you jump, you become a free body, totally disassociated with your container, the elevator. If instead you were statically suspended, there would be an interaction between you and the elevator, which would add all your weight to the whole system.

However, since momentum is conserved and all that, you impart the same force by jumping on the elevator, over time, that you take away during your flight. So, if you average your weight contribution to the elevator over time, it comes out the same as if you just stood there.

Brownout...nice catch!

As far as your last couple of sentences quoted above.

Split Infinity

 

Thank you very much, Brownout....
Yeah...I changed the subject to a new situation....
Thanks for the explaination...I got it.
D.

 

I just thought of something.

Now in my example where you have two elevators...one filled with air and one with water and a person is inside each.

In the one filled with air as the person jumps we know that the person is separating their applied weight to the elevators floor so after the initial addition of force from the jump...the weight of the elevator is reduced while that person is airborne and thus there is less tension and stress placed upon the cables as opposed to the person suspended in the elevator with water where the persons weight cannot be separated from the elevators floor as there is a water column between the person and the elevators floor that connects the persons weight to the elevator.

Now I just thought...in the air filled elevator...because the air cannot act in the same manner as the much denser liquid that is water...the person can jump and remove their weight for a time while they are airborne...BUT...this is simply because of the Geometry of the elevator and the persons body.

If the elevator was shaped the same way as a persons body is lying either face down or upon their back...and that elevator shape was perfect to say the form of a naked body...a person could be suspended under a column of AIR as if their body was acting like a snug bottle cork...and basically so snug as to slide into this body shaped elevator to the point where the persons weight compresses the air to the maximum point whatever their body weight will compress this column of air.

So in this case...no matter what the material filling such an elevator might be...Gas, Liquid, Solid...and no matter what that materials density...as long as the geometry of the elevator does not allow for the material to pass by the body or any other possible object that is not permeable...that body or object will suspend itself atop those materials at a level at which the body or objects weight has compressed such materials down to.

Just a thought.

Split Infinity

 

And just to add to that...because even air can suspend a body if the geometry will allow it...that body even if not touching the elevators floor will never have it's weight disconnected from the floor thus even a body suspended by air will keep the stress and tension of the cables constant.

Split Infinity

 

Is it possible to google up a web site for people with VAST KNOWLEDGE about everything, SEVERAL LIFETIMES of experience, SUPREME PERFORMANCE at EVERY POSSIBLE activity and a few impossible activities, from walking the bottom of the Mariannas trench to playing dominoes to flying to the moon by flapping their arms? I mean the kind of person that climbs the highest mountain on the planet and takes a step ladder with him so he can climb the highest mountain PLUS SIX FEET after coming back from Mars in a space ship he designed for himself with a little bit of cheating by reading the TOP SECRET plans he was delivering to the PENTAGON from the ALIENS at AREA 51?

or is it allaboutcircuits.com and I'm just now realizing it?

 

Is it the new version of allaboutcircuits; allaboutsplitinfinity.com that your looking for?

 

Is it possible to google up a web site for people with VAST KNOWLEDGE about everything, SEVERAL LIFETIMES of experience, SUPREME PERFORMANCE at EVERY POSSIBLE activity and a few impossible activities, from walking the bottom of the Mariannas trench to playing dominoes to flying to the moon by flapping their arms? I mean the kind of person that climbs the highest mountain on the planet and takes a step ladder with him so he can climb the highest mountain PLUS SIX FEET after coming back from Mars in a space ship he designed for himself with a little bit of cheating by reading the TOP SECRET plans he was delivering to the PENTAGON from the ALIENS at AREA 51?

or is it allaboutcircuits.com and I'm just now realizing it?

So...I see that you are responding on this topic to a post I made on another now closed topic.

So Mods...since you have not moderated this above post am I to assume such activity is now sanctioned?

I was under the impression that once a Topic is closed to either open another topic detailing the same thing or using another open topic as a way to continue discussing and responding to the now closed topic was forbidden.

Is this the way you want to do things here?

Split Infinity

 

Not really, we are watching you closely. You have been getting a bit spammy lately, 5 posts, really long ones, in a row on the same thread, not to mention the other posts on other threads at the same time?

Look around, most folk post short concise posts. We don't claim extraordinary knowledge in a multitude of subjects. The subjects we know we know extraordinarily well, but do not feel the need to toot our own horn all the time. This is considered spamming. Frankly it does not improve your reputation, but gives it a major negative hit. You are among adults. Frankly I have given up trying to discuss anything about you, not once have I seen you acknowledge where you were wrong.

I know nothing about you. No one does. We judge you by the quality of your posting, which frankly as been very low. Any personal information you give is how you are a major figure in various projects, and how you can't talk about it because it is a secret. More spamming, in other words.

Generally the moderators on this site are very hands off except where we have no choice. This has worked in your favor, but there are limits. All of us are watching you pretty closely, and discussing your behavior on this site.

I have said this before, the more time I have to spend watching the non electronic areas reduces the time I spend doing what I really like. I joined this site because I like electronics, make that love electronics. I also have about 3 or more projects lined up that keeping up with you cuts into.

We do not use the reputation system here. We do have a "Thanks" system instead to show posts we like or agree with (usually both). How many "Thanks" have you gotten since you have been here? This is a good judge of quality.

Points in your favor are you don't seem to feel the need to edit old posts (practice revisionist history) and seem to be able to refrain from flaming. Many of the negative comments you are getting are not ad hominem comments, but pointing out specific behaviors we find objectionable. We have moderated several personal attacks toward you and warned the other users, as is our job.

I will say this again:

1. Short concise posts, no walls of text.
2. No claims of expertise you don't have.
3. Show citations (see #2).

You asked publically, so I answered publically.

This thread has drifted radically off topic. I have a choice to split it or close it. Since the OP's main question seems to have been answered I will close it. If he objects he can sent me a PM and I will split the closed portion and reopen the Going Fishing thread.