Actual Working of Weighing Machine (Normal vs gravitational force)

[Orodruin]

That is not how I would interpret this OP statement in post #1 (color emphasis mine)

(Even though I said I would not post any more here, I had to reply.)

That is an interpretation, but the OP also says “when a person stands on”. If you look at the attempted FBD in #5, it certainly seems like the mg force is related to the person rather than the scale.

I am not saying I cannot see your interpretation. I am saying it was a bit over the top to call out everyone ignoring the mass of the scale when their interpretation of the OP was equally valid (and the one OP intended).

 

[kuruman]

I am saying it was a bit over the top to call out everyone ignoring the mass of the scale when their interpretation of the OP was equally valid (and the one OP intended).

It certainly was not my intention to "call out everyone" and, if my post seemed to indicate that, I apologize to all. My point of view is that it makes no sense to draw a free body diagram for a system with zero (or negligible) mass. FBDs serve as guides for writing Newton's second law which requires a non-zero mass to make sense. I will say no more.