I'm not sure I'm following you correctly, but it sounds like you're supposing that re-zeroing the scale is accomplished by changing the position of the zero mark (but not the position of the 50-lb mark). But that's not how the scale works. The zero mark is printed on the beam; it can't move...
I'm having a bit of trouble following that.
Maybe it would be easier if we try to separate the effects of adding weight and shifting the center of gravity. We want to add weight; we don't want to shift the center of gravity (unless it doesn't matter anyway).
So, suppose we keep the weight the...
This did occur to me, and I also worried about the fact that the sliding weight hangs from the beam in two places, not only one. But then after thinking about it some more, I concluded that re-zeroing the scale after adding to the sliding weight would take care of these things. Do you agree...
Ok. But I don't see where I did otherwise. The smallest division on my balance is 0.1 g, and I increased that to 0.2 g to allow for the difficulty of reading it.
Pretty sure.
I have a Roberval balance that's graduated in tenths of a gram, although parallax makes it hard to read the pointer that precisely. So, let's say +- 0.2 g. It can weigh up to 210 g using the pair of sliding weights that are part of it, and more than that if I place known weights...
I don't understand. Wouldn't a misplaced fulcrum or a sliding balance weight that's too heavy or too light both cause a percentage inaccuracy? Not zeroing the scale via the movable counterweight would cause a constant weight discrepancy, I think, but I did zero it.
The scale seems to have...
Yes, my scale has that. It's for zeroing the scale. That is, you're supposed to set it so that the beam is balanced when the sliding weights are both at zero and no weight is on the scale, which is what I did. But if, after that's done, the scale reads the wrong weight when something is...
I have a scale, the kind for weighing people, and I'm trying to calibrate it. It uses sliding weights, not springs. You step on the scale and then slide the two weights along the beam until it balances. Suppose I keep the smaller weight at zero and slide the larger weight to the 50-pound mark...