Measuring Objects using Dissimilar Units

In summary, the conversation discusses the possibility of measuring speed in quantum terms and the dilemma of calculating objects with different units. It is argued that adding and subtracting quantities with different units is not meaningful, but multiplication and division are precisely defined operations. The question is raised about measuring speed in quantum terms and the trade-off between accuracy in measuring momentum and position.
  • #1
Tom Bruce
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Quantumly speaking: Can speed be measured? If so, why? If not why?
This is a serious question. Speed involves a distance unit and a time unit. For example .. "ft/sec" .. and it is illogical to divide seconds into feet. Having made this point can speed be quantumly measured and how do you resolve this dilemma i.e calculating objects defined by using dissimilar units.
 
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  • #2
Tom Bruce said:
t is illogical to divide seconds into feet

This is the part where I think you need more work. What is illogical about wondering how many feet an object travels in 1 second?
 
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  • #3
mfig said:
This is the part where I think you need more work. What is illogical about wondering how many feet an object travels in 1 second?
... or the difference between a carton that holds 12 eggs and a carton that holds 18 eggs? Or the amount that my paycheck will increase if I put in another hour this week (zero, at the pay scale for Physics Forums staff, but that's neither here nor there), or ...

Adding and subtracting quantities expressed in different units is not meaningful, but multiplication and division are precisely defined operations with logical meanings.
 
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  • #4
Tom Bruce said:
it is illogical to divide seconds into feet.
It works for sharing sweets amongst n kids and it works for sharing feet out amongst the n seconds that are available.
Division is an 'allowed' mixed unit or mixed quantity operation. Addition is not; 3 miles + 1 hour has no meaning and 3 miles+1km is not convenient.
 
  • #5
Tom Bruce said:
Quantumly speaking: Can speed be measured? If so, why? If not why?
This is a serious question. Speed involves a distance unit and a time unit. For example .. "ft/sec" .. and it is illogical to divide seconds into feet. Having made this point can speed be quantumly measured and how do you resolve this dilemma i.e calculating objects defined by using dissimilar units.
What do you mean by "quantumly measured"?You can measure the momentum of a particle as accurately as you like, but the more accurately you measure the momentum the less accurately you can measure it's position.
 

1. How do I convert between different units of measurement?

To convert between different units of measurement, you need to know the conversion factor between the two units. This can usually be found through a quick internet search or in a conversion chart. Then, simply multiply the measurement in one unit by the conversion factor to get the equivalent measurement in the other unit.

2. Can I measure an object using both metric and imperial units?

Yes, you can measure an object using both metric and imperial units. However, it is important to keep in mind that the two systems of measurement use different units and conversion factors, so be sure to convert all measurements to one system for accurate comparison.

3. Why is it important to use the correct units of measurement?

Using the correct units of measurement is important because it ensures accuracy and consistency in measurements. Different units may have different scales or sizes, so using the correct units allows for proper comparison and understanding of the measurement.

4. How do I measure an object without a ruler or measuring tape?

If you do not have a ruler or measuring tape, you can use common objects as a reference for measurement. For example, you can use your hand or a pencil to estimate the length of an object. You can also use a string or piece of paper to measure and then compare that to a ruler or measuring tape.

5. Can I use fractions or decimals when measuring an object?

Yes, you can use fractions or decimals when measuring an object. Make sure to use the correct units and convert between fractions and decimals if needed for accuracy. For example, you may need to convert 1/2 inch to 0.5 inches for precise measurement.

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