Is it possible to measure SQRT(2) kg with a scale?

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Homework Help Overview

The discussion revolves around the feasibility of measuring an irrational quantity, specifically ##\sqrt{2}## kg, using a scale. Participants explore the implications of irrational numbers in measurement and the accuracy limitations inherent in any measuring process.

Discussion Character

  • Conceptual clarification, Assumption checking, Mixed

Approaches and Questions Raised

  • Some participants argue that measuring an irrational quantity is impossible, while others question the accuracy required for such a measurement. There are suggestions to construct a physical representation of ##\sqrt{2}## using geometric methods, prompting further inquiries about measurement accuracy and construction errors.

Discussion Status

The discussion is active, with various viewpoints being explored regarding the measurement of irrational numbers. Participants are questioning assumptions about the nature of measurement and the role of accuracy, with some providing counter-proposals and others emphasizing the limitations of standard scales.

Contextual Notes

Participants note that any measurement has a margin of error and discuss constraints related to the construction of objects representing irrational lengths. There is mention of imposed homework rules regarding the use of standard scales for such measurements.

littlemathquark
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Homework Statement
İs it possible to measure ##\sqrt{2}## kg with a scales?
Relevant Equations
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Because of ##\sqrt{2}## be a irational numbers I think it is impossible and there is no scales that can measure irational quantity. May be approximately. But 2 kg can be measurable. İt is my efforts and thougts.
 
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littlemathquark said:
Because of ##\sqrt{2}## be a irational numbers I think it is impossible and there is no scales that can measure irational quantity. May be approximately. But 2 kg can be measurable. İt is my efforts and thougts.
It's impossible, but not because the number is irrational. To what accuracy do you propose that this measurement be made? Any measurement is impossible to make beyond a given accuracy.
 
I will offer a counter proposal, make a square with side lengths equal to the unit of your choosing, make an object with the lenght of the diagonal of the square. Now your object has a length of ##\sqrt{2}## units.
 
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pines-demon said:
I will offer a counter proposal, make a square with side lengths equal to the unit of your choosing, make an object with the lenght of the diagonal of the square. Now your object has a length of ##\sqrt{2}## units.
I repeat, to what accuracy?
 
kuruman said:
I repeat, to what accuracy?
As good as your square is. If you make it really straight, thermal fluctuations may average any irregularity out.

Edit: What you are not allowed to do is take a regular scale and try to find ##\sqrt{2}## units in that scale.
 
Last edited:
kuruman said:
It's impossible, but not because the number is irrational. To what accuracy do you propose that this measurement be made? Any measurement is impossible to make beyond a given accuracy.
If it's impossible for ##\sqrt 2##, then it's impossible for any number. Every measurement has a margin of error.
 
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pines-demon said:
Edit: What you are not allowed to do is take a regular scale and try to find ##\sqrt{2}## units in that scale.
I don't see why not. You use your trick to get a length of ##\sqrt 2## and then use that on a scale.
 
pines-demon said:
I will offer a counter proposal, make a square with side lengths equal to the unit of your choosing, make an object with the lenght of the diagonal of the square. Now your object has a length of ##\sqrt{2}## units.
No it doesn’t. You have an object that is ##\sqrt 2## units within the errors of your construction.


pines-demon said:
As good as your square is. If you make it really straight, thermal fluctuations may average any irregularity out.
On the contrary. Thermal fluctuations add to the construction error.
PeroK said:
If it's impossible for ##\sqrt 2##, then it's impossible for any number. Every measurement has a margin of error.
obviously…
 
Orodruin said:
On the contrary. Thermal fluctuations add to the construction error.
There is also thermal expansion.
 

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