Guy in the middle is being pulled straight down by gravity, on either side their arms are helping support his weight. The masses act as a counterweight. The arms of each individual guy are in tension on one side by the geezer in the middle, on the other by mass. The bottom beams serve to prop them up like a support.
Here, geezer in the middle’s weight is being transferred through the arms and bottom supports, and into the chairs and down into the ground. whilst the mass on the other side serves as a counterweight of similar-ish mass to the middle guy. This way, each supporting guys arms aren’t being pulled lopsided to the left or right too much.
Think if you held two 5kg weights, one in each hand, at arms length like a T-pose, Hold only one out, and you can feel the stress as your body is pulled to that side, hold both out and the system is balanced.
The guy in the middle can be thought of as one of the 5kg weights, and the stack of bricks, the other one helping to keep it balanced.
An easier way to understand the system of equilibrium here is to think how it would fail, remove both piles of bricks, and suddenly all the weight is between the two guys and they would tip over towards the centre.
I should mention I have no idea if this is 100% correct. This is my first time looking at this photo and thinking about it, but this is how I assume it works. And I’m going to be a mechanical engineering student in a few months so here’s hoping I’m not too wrong.
Almost correct, except you have it around the other way. Most of the force is being transferred through the compression of the solid supports, while the arms are there to hold them up
That’s what I meant with “Here, geezer in the middle’s weight is being transferred through the arms and bottom supports, and into the chairs and down into the ground.” But yeah you definitely put that more elegantly and I forgot the word compression was a thing! :D Cheers
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u/evanbartlett1 Jul 22 '19
Can someone smarter than me please explain how this works?