johannesbender wrote: ↑Tue Nov 19, 2024 7:05 pm
@Fletcher afai can see , the rod measures around -6 watts on activation for a small period of time .
Hey jb .. if there was a significant loss of watts in the rod 'coming live' I would expect the velocities of B1 and B2 to be slightly less than the control weight A1 - they are the same, lock stock and smoking barrel ..
** When all boiled down all I am saying is that momentum is conserved in Classical Physics and the program ( this appears the case in the real-world too ) - however, because we are sim-experimenting with a very simple arrangement, that is physically constrained to x-axis linear movements only, then we see a loss of capacity to do Work after the pull-along ( KE < expended WD ) - that loss of potential capacity to do Work is not stored in the substrate of the objects as internal and/or connections stressors/tensors etc, or the program software - as far as I can tell it comes about from mechanical limitations to the build design itself - its current arrangement does not allow the unrealized potential capacity to do Work to manifest imo ..
I just made a quick sim you can download - bigger scale with rope tensions and power metered ..
Top one has 0.0 Elasticity and bottom one has 1.0 Elasticity ( theoretical range is 0.0 full deformation losses to 1.00 perfect elasticity ) ..
I think I've mentioned it before that elasticity on ropes doesn't appear to change in my program i.e. bug - sim shows same results - try replacing with a stiff spring/rod etc if you think it makes a big difference ..
...............
fwiw for many years I asked the question here about sim programs building from bottom up or top down - I could never get a answer I could make sense of - these simple sims and their kin helped me to decide they likely built from bottom up, prioritizing vector Conservation of Momentum ( as it should be imo ) ..
Sorry T .. I was on a very short coffee break and it was a 2 minute sim .. knocked off for the day so came back and changed the rope connection for a pulley that I know the elasticity works fine - hardly makes any difference until elasticity gets closer to 1.00 and even then not much - n.b. see the acceleration and velocity vectors changing to show it is working .. sim below ..
Only just had time to download and look at your sims properly.
WDtoKETest1E1:
The deep dive, I don't completely understand why the relationships exist as they do here.
Force x time isn't energy, which is why the 1kg has twice the KE of the 2kg in the first place. You then add another KG to the mix after it has accelerated, and efficiently tether them together. Somehow now the KE the 2kg and the 1+1kg are again both the same.
I tried editing the sim, but I broke it. If the 2 x 1kg start at the same spot on the X=0 line and you perform the test again, I think once the dust settles, the COM of the 2x1kg weights will be at the same X position as the 2kg weight. So the work done on the COM is the same, but because the application of the force was on a component that wasn't directly tied to the COM we have a difference in work done.
So back to Dax's question, can we reverse the process to get a gain in KE?:
What is the specific mechanism that causes the KE loss...So the 1kg mass has a sudden interaction with another mass at a different energy level, or at a different energy reference. The energy is instantly split between the two masses.
I tried crashing 2kg into a spring, then disconnecting 1kg and releasing the spring with the remaining 1kg, but the spring gives back the same energy you apply to it, regardless of weight.
I attached a sim of my second attempt, where two masses have 12.5J of KE each. They suddenly attach to a "massless" lever, one at 1/8 from the pivot compared to the other, so the closer mass would have to give its energy to the other. This just became another instance of energy suddenly vanishing.
thx4 wrote:@Fletcher, Is the software gravity set to 0 ?
Hi thx4 .. all my sims in this thread are with gravity ON .. in this example gravity on or off doesn't make any difference to anything as objects can only move horizontally ( don't change gravity PE i.e. GPE ) .. they have a known mass, which is also their inertia, and inertia is effectively a measure of an objects resistance to a change in motion when a force either accelerates or decelerates it ( re. Newton's Laws ) ..
fwiw .. all objects with a mass have invariable inertia proportional to their mass - even when able to free fall vertically under gravity the inertia is always present and resists change in vertical motion .. I think of it like this - each atom has inertia - a group of atoms add up to make a mass - the total inertia of the mass is equal to the summed inertia of each atom in the mass - all the atoms communicate with their immediate neighbours to hold their structure/form or lattice ( nuclear forces ) - when a force is applied to a mass like in the sims it doesn't matter on which atom it is applied i.e. it doesn't have to apply at the COM, it physically is applied at the nearest face presented to it ( in the sim I show it applied at the COM's but it could also be the nearest face ) - consequently all distances are measured relative to that interface point ..
Last edited by Fletcher on Thu Nov 21, 2024 1:32 am, edited 1 time in total.
daxwc wrote:So Fletcher where we headed with the “Raising GPE without using Law of Levers ? ..” and ganging? A type of chain syphon?
I want a little meat with my potatoes ;)
... Or did I just get the meat and looking for potatoes.
Hey dax .. the title to the thread is still my aim to show, and I haven't lost sight of it - but I am laying down foundations because I'm going to build-on from that, and apparently there is some mileage in the foundations discussion yet before we have a reasonable consensus ..
On the matter of 'meat and potatoes' you've actually been getting a little of both - soon I will throw out the rope/pulley/spring etc etc pull-along method and reformat the sim experiments to do away with them entirely ( they are a non-event ), and get onto things that I believe are much more interesting, and hope you will too ..
So for now it's more hot water soup and dry bread ;7)
P.S. I'll get the the last 2 posts from T and jb when I can find the time to do them justice ..
Last edited by Fletcher on Wed Nov 20, 2024 11:18 pm, edited 1 time in total.
Fletcher wrote: ↑Wed Nov 20, 2024 11:00 pm
Hi thx4 .. all my sims in this thread are with gravity ON ..
Salut Fletcher,
Je me posais simplement la question de savoir sur quoi reposait tes objets, sur le sol, dans l'espace, etc, il y a forcement une trainée...
J'ignore si le WD en tient compte.
Hi Fletcher,
I was just wondering what your objects are resting on, on the ground, in space, etc., there's bound to be a trail on the ground...
I don't know if the WD takes this into account.
Not everything I present is functional, but a surprise can't be completely ruled out.Greetings.
Only just had time to download and look at your sims properly.
WDtoKETest1E1:
The deep dive, I don't completely understand why the relationships exist as they do here.
Force x time isn't energy ( true - it is momentum change ), which is why the 1kg has twice the KE of the 2kg in the first place. You then add another KG to the mix after it has accelerated, and efficiently tether them together. Somehow now the KE the 2kg and the 1+1kg are again both the same. ( inertia )
I tried editing the sim, but I broke it. If the 2 x 1kg start at the same spot on the X=0 line and you perform the test again, I think once the dust settles, the COM of the 2x1kg weights will be at the same X position as the 2kg weight( yep, most likely - may sim that tomorrow as a further test ). So the work done on the COM is the same, but because the application of the force was on a component that wasn't directly tied to the COM we have a difference in work done. ( Work Energy says force x distance i.e. that's the actual physical distance the force is applied - it is the actual distance a force is applied that supposedly dictates the WD .. )
So back to Dax's question, can we reverse the process to get a gain in KE?: ( that would be an interesting proposition indeed )
What is the specific mechanism that causes the KE loss...So the 1kg mass has a sudden interaction with another mass at a different energy level, or at a different energy reference. The energy is instantly split between the two masses. ( momentum sharing/transfer )
I tried crashing 2kg into a spring, then disconnecting 1kg and releasing the spring with the remaining 1kg, but the spring gives back the same energy you apply to it, regardless of weight. ( because a spring stores elastic potential energy ( capacity to do work ) and then gives it back as KE ( capacity to do work ) - it does not store and release momentum ( not equivalent to energy )
I attached a sim of my second attempt, where two masses have 12.5J of KE each. They suddenly attach to a "massless" lever, one at 1/8 from the pivot compared to the other, so the closer mass would have to give its energy to the other. This just became another instance of energy suddenly vanishing. ( in this instance IINM we have an added problem because the experiment is pivoted to the background - momentum is not conserved because the 2 weights are torquing each other and the pivot point - and leverage applies - result is we lose some momentum to the background movement ( which we don't see on the screen )( have to infer ) - the program is really quite clever really to know to do this ..
Fletcher wrote:
Hi thx4 .. all my sims in this thread are with gravity ON ..
Hi Fletcher,
I was just wondering what your objects are resting on, on the ground, in space, etc., there's bound to be a trail on the ground...
I don't know if the WD takes this into account.
Hi thx4 .. since there are no frictions and no air resistance etc ( just mentioned above ), then they are positioned in space examples, say above the earths surface on a frictionless slide attachment anchored in space i.e. they have inertia but have no physical connection to the earths surface - a "pure' experiment ..
Last edited by Fletcher on Thu Nov 21, 2024 7:33 am, edited 1 time in total.
Sorry for poking the bear Fletcher couldn’t resist. I am an impatient little fuvker. 8)
Fletcher: The deep dive, I don't completely understand why the relationships exist as they do here.
Force x time isn't energy ( true - it is momentum change ), which is why the 1kg has twice the KE of the 2kg in the first place. You then add another KG to the mix after it has accelerated, and efficiently tether them together. Somehow now the KE the 2kg and the 1+1kg are again both the same. ( inertia )
I know I have put this video on here before might help some people understand. So the first part of the video is Fletcher’s SIM from a different perspective. It is the first half of Fletcher's SIM. https://www.youtube.com/watch?v=4lC2bzXZq7I
How does the SIM handle the transition ( which isn’t shown) in Fletcher’s SIM ? Did it change formula’s to a jerk? Did it forget the reactive force's energy into the first mass it takes energy to slow it down? - Doesn't that imply missing energy out of the system?
I know already stated; Momentum and Energy. Although it is intriguing not sure a SIM coding work around is worth the effort other than using it as a sign post and move on. Do we have a physical example where it seems too much energy has been lost?
Last edited by daxwc on Thu Nov 21, 2024 2:09 pm, edited 2 times in total.
Now that it is getting colder outside, I think that I will move my grinding operations indoors. I think that will help me get more work done in less time. Also, it is climate controlled so I will not have to worry about the steel rusting from condensation.
I have experienced tools rusting over one winter when they were left uncovered in the garage. I learned from a power tool manufacturer on a support call that temperature fluctuations from night to day cause condensation. So, I am thinking that bringing parts from outdoors to indoors will also cause condensation.
The power tool company told me to either coat the tools in oil or wrap them in bubble wrap. A friend told me that things need to be sealed up. However, I learned from observation that covering over the top works just fine. I use 45 gallon outdoor plastic bags to quickly cover over the top and sides of my power tools whenever I am finished using them, which has effectively prevented them from rusting for the last few years. So, my conclusion is that the water from the air that condensates is subject to gravity and cannot rise upward.
With all of that being said, it is cold outside and I am going to bring my grinding operations indoors.
Last edited by spinner361 on Thu Nov 21, 2024 8:03 pm, edited 2 times in total.