Thread: The measurement of mass

Mass is not weight -- True or false?
Mass is an inertia measurement and a quantity of matter? If we put two different masses on a see-saw they balance at different distances from the fulcrum. Now if we increase their size by the same amount, they still balance at the same distance from the fulcrum.

Conclusion? Mass is independent of size and size is an amount and therefore mass is not a quantity of matter -- Sir Isaac Newton erred.

Further conclusions:
Relativity matters: there is no absolute mass. Measurement is the building of a set that compares the elements of the set. The correct set and not just any set is required.
Mass as an inertia measurement or comparison is correct, and mass as a quantity of matter is incorrect.

Is mass: mL-squared = mL-squared on a see-saw? Or is mass the weight because 'a' in W = F = ma is 'g' a constant on each side? And so mL =mL?

Now I beleieve a FMMC electrical meter measures the inverse of mass in its needle-deflection amount. Therefore someone could find a way to correlate the two and show the meter measures mass and show how the see-saw measures mass. (Of course there are other ways to measure mass.)

Originally Posted by Joshua Stone

Mass is not weight -- True or false?
Mass is an inertia measurement and a quantity of matter? If we put two different masses on a see-saw they balance at different distances from the fulcrum. Now if we increase their size by the same amount, they still balance at the same distance from the fulcrum.

Conclusion? Mass is independent of size and size is an amount and therefore mass is not a quantity of matter -- Sir Isaac Newton erred

This is gibberish... I'm a biologist, but someone with only a basic understanding of high school physics could tell this is nonsense.

How are you defining increasing their size by the same amount. If you mean adding the same amount of mass to each, your conclusion is wrong.

m1 = 5 kg
L1 = 2 m
m2= 4kg
L2 = 2.5 m

If you increase the mass/weight of say m1 and m2 by 0.5 kg and kept m1 at the same place. L2 would have to be placed at 2.2. m from the fulcrum to balance.

Or, if you mean changing the dimensions by some sort of factor of its current size, or changing the volume by some factor, in which case if the two masses are not already the same "size" and density your conclusion is wrong. Why would they balance.

For the sake of argument let's imagine your weights are ice cubes with a density of 0.91 g/cm3

Ice cube 1 is 5 by 5 by 5 cm then m1 = 113.75 g
Ice cube 2 is 4 by 4 by 4 cm then m2 = 58.24 g

This time they're on an itty-bitty seesaw.

L1 = 0.05m
L2 = 0.097m

If you double the volume of ice cube one, m1 becomes 227.5
If you double the volume of ice cube 2, m2 becomes 116.48

In which case yes they balance at the exact same distance from the fulcrum as above, i.e. at different distances.

I don't know how you define "size," but unless it's in some sort of radically different way than I've ever seen before, you're wrong. If you by chance mean changing the dimensions by a certain factor, then the effect is the same, the distances they balance at will not change.

Originally Posted by Joshua Stone

Mass is not weight -- True or false?

True. Did someone say it was?

Originally Posted by Joshua Stone

If we put two different masses on a see-saw they balance at different distances from the fulcrum. Now if we increase their size by the same amount, they still balance at the same distance from the fulcrum.

I take this to mean that you have increased the overall dimensions of the mass and thuse reduced its density. further this change has not altered the centre of gravity of the mass. If these conditions are met than your conlusion is correct.

Originally Posted by Joshua Stone

Conclusion? Mass is independent of size ....

as stated, this is meaningless since you have not defined which mass you are referring to, nor have you defined what you mean by size. Beyond that, at its basic level, it is a trite observation. No one is claiming that mass is dependent on size.

Originally Posted by Joshua Stone

Conclusion? Mass is independent of size and size is an amount and therefore mass is not a quantity of matter.

Originally Posted by Joshua Stone

...Sir Isaac Newton erred.

:?

Thereafter your post appears to descend into the absurd.