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Questions tagged [measurements]

For questions related to methods, analysis, accuracy, presentation, or interpretation of measurements. It is not intended for abstract quantum measurement questions such as how a wave function collapses during measurement or how the Heisenberg uncertainty principle constrains quantum measurements.

Measurement is the process of quantifying an attribute of an object, event, or system. Scientific measurements always consist of a definition of what is being measured, numerical values for the magnitude and uncertainty of the measured quantity, and the measurement unit.

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How do I experimentally measure the surface area of a rock?

I hope this is the right place to ask this question. Suppose I found a small irregular shaped rock, and I wish to find the surface area of the rock experimentally. Unlike for volume, where I can simply use Archimedes principle, I cannot think of a…
Pritt Balagopal
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What does multiplying two real-world values represent?

I totally get what division means in the real world. "dollars / hour", well, that's the number of dollars you will make in one hour. "kilometers / gallon" is the distance you can go with a gallon of gas. Division means that given a certain amount…
Brian Risk
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How to (safely) measure the surface area of a human body?

Here's a question just for curiosity. You measure mass on scales. You could measure volume by submerging in a bath with a snorkel system. But how could you measure a living human's surface area without harming. Ideas so far: Using software to make…
CJB
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What near-future measurement technique improvements will extend our physical knowledge?

Inspired by the wiki-article on atom-lasers: Another application, which might also benefit from atom lasers, is atom interferometry. In an atom interferometer an atomic wave packet is coherently split into two wave packets that follow…
Werner Schmitt
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What is the 'complete' number system to measure objects we see in reality?

It is clear that we need at least the real numbers to measure lengths as it is very easy to construct a length of $\sqrt{2}$ geometrically. However, consider every physics situation where we want to measure some thing (eg: length , mass time etc )…
tryst with freedom
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Where to measure?

In all my experiments (at the university) so far, I nearly always took my measurements on an equispaced grid over the whole measurement space. And now I asked myself, why? Is there a theory of where to place your measurements for max efficiency? And…
Dominic Hofer
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Why are all basic physical measurements ratios?

Why is it that "all basic physical measurements [...] are ratios"? This question comes from the book Mathematical Physics by Donald H. Menzel. Here is the explanation given: 1. The significance of an observation. Any direct observation of a…
Randy Randerson
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A method/device for measuring angles, as an experiment?

What's the best device for measuring angles, as an experiment for a fundamental physics lab at the university level? The first experiment in our fundamental physics lab is "Measuring & Measurement errors". Currently we have four devices: - rule (0.5…
mini
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Measurement using Vernier Callipers

The diameter of a cylinder is measured using a Vernier Callipers with no zero error. It is found that the zero of the Vernier scale lies between 5.10 cm and 5.15 cm of the main scale. The Vernier scale has 50 divisions equivalent to 2.45 cm. The…
Utkarsh
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Measuring low frequency sound waves (infrasound?) coming from a neighbor

I live in upstate NY and have a neighbor who is using what I believe is an infrasound Rodent Deterrent system in his camper ~30 feet away from our house (the waves permeates the entire house). The pressure can be "felt" in the ears but aren't…
Stephen Jung
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Name of the method used to measure the diameter of a ball

Is there a name for the method used to measure the diameter of a ball, specifically, using two wooden blocks and measuring the gap between them?
Justin
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Cup anemometre can measure 3D wind component?

As part of my PhD thesis I am looking for information about anemometres. I have heard that cup anemometre can only measure the x and y component of the wind, the z being left out because it measures the wind thanks to moving part. I have been…
Ryderc
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Calculating Uncertainty with Mean Absolute Deviation

I'm taking an Introductory Physics course and, when learning about approximating uncertainty, I was wondering if a more quantitative method would be to calculate the Mean Absolute Deviation using the data? The way I learned in the past was to…
K Ferreira
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Is the coincidence between these large numbers purely accidental?

Following are 3 sets of some very interesting data: Size of proton- $10^{-15}$m Size of observable universe- $10^{26}$ m Mass of an electron- $10^{-30}$ kg Mass of observable universe- $10^{55}$kg Life span of the most unstable particle-…
SirXYZ
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Vernier Caliper the principle behind it

I know how to use a caliper but on what principle does devices like caliper and screw gauge works. Can someone derive its formulae. I am more or less interested in its mathematical aspect.
Einstein'sLover
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