Why so quick to discount gravity? Along with momentum, gravity is an important component as it provides potential energy. Even the "horizontal" chain video experiences a loss of potential energy. That is, we are expending energy to overcome losses due to the motion of the chain. Show me a video of a chain being slung from one end of a flat table to another and not onto the floor as in the later video.
Another effect of gravity is that for a dropped object, up to a point, it's velocity increases over time. Gravity causes acceleration. However, since we are talking about a chain the leading end of the chain cannot move any faster than the trailing end. I would posit that the higher the beaker is held the faster it will empty. I doubt that the beaker would empty if it was setting on the floor no matter how hard (within reason) the initial tug. That is, the greater the change in potential energy the higher the steady-state velocity (and likely the higher the lift).
Why does it lift? Hmm... This type of chain doesn't bend ninety degrees between adjacent beads. To make the turn it has to "rainbow" For the beaker, the chain must turn 180 degrees (up out of the beaker then turning down). For the "horizontal" the chain must turn 90 degrees. Since both ends of the chain are traveling at the same velocity, the trailing end coming out of the beaker has a certain momentum due to its velocity in turn due to the change in potential energy. To change the direction (momentum) takes force over time due to energy). The higher the velocity, the higher the lift(?).
Also, consider a siphon hose. Ignoring losses, all that really matters is that the outlet is lower than the inlet. In between, the hose can be at any height either below or above the end points. Other than the difference in the endpoints, all the other force and momenta differentials at the various elevations cancel out. I believe we have a similar situation with the beaded chain. However, as an aside, in this case the "fluid" in motion is not constrained by the hose and can get "squirrely" as observed.
The preceding not worth $0.02.
Last edited by Hoosier_Beagler; 07/22/21.
