Name: measurement units, standards, and si basics
Uploaded: 2023-09-22T11:49:38.000Z
Duration: 1 min 10 s
Channel: JoVE

Физическая величина – это любое число, которое количественно описывает физическое явление. Например, длина — это физическая величина, описывающая расстояние между двумя точками.
Измерения физических величин выражаются в единицах. Масса вашего тела может быть выражена в килограммах, а ваш рост — в метрах.
Физические величины, выраженные без стандартных единиц, трудно понять. Например, если высота Эйфелевой башни равна 300, то без указания единиц измерения контекст числа будет неясен. Это означает, что Эйфелева башня может быть относительно высокой или очень низкой.
Для того, чтобы точно измерять и сообщать о различных свойствах вещества, была разработана общая система измерений, известная как Международная система единиц или единицы СИ.
Система СИ рекомендует использовать семь базовых величин и их единиц измерения, которые образуют Международную систему величин.

Единицы измерения и эталоны

Units and Standards of Measurement

Физической величина определяется либо указанием способом её измерения, либо указанием, как она рассчитывается на основе других измерений. Например, рассмотрим металлический куб. Мы можем определить его массу и размеры, указав методы измерения, такие как использование весов и метровой линейки. Затем мы можем определить объём, заявив, что это куб его стороны, и мы можем рассчитать плотность как массу, делённую на объём.

Измерения физических величин выражаются в единицах, которые являются стандартизованными значениями. Например, длина стороны куба, являющейся физической величиной, может быть выражена в метрах или сантиметрах в зависимости от размера куба.

Существуют главным образом две системы единиц. Первая — это метрическая система, использующая СИ-единицы, а вторая — это привычная или имперская система, использующая английские единицы. СИ — это международное сокращение от французского Système International d'Unités. Она является наиболее широко используемой системой единиц во всём мире и считается стандартной системой учёными и математиками.

Этот текст адаптирован из <a href="https://openstax.org/books/university-physics-volume-1/pages/1-2-units-and-standards">Openstax, University Physics Volume 1, Section 1.2: Units and Standards.</a>

Физическая величина определяется либо путем указания метода ее измерения, либо путем указания способа ее вычисления на основе других измерений. Например...

Education

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Mechanical Engineering

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Unit 1

Раздел 1

Physics Basics

Основы физики

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

measurement units, standards, and si basics

Measurement units, standards, and SI basics help scientists describe physical quantities clearly. A unit gives a number meaning, while a standard provides a fixed reference for that measurement. Together, they make results easier to compare and understand.

The International System of Units, or SI, is the most common measurement system in science. It uses agreed-upon base units for common quantities. These standards reduce confusion when measurements are shared across labs, classrooms, and countries.

Using the same units and standards also makes data more reliable. It allows students and scientists to compare measurements and communicate results with less error. This foundation is essential for accurate work in physics, chemistry, and other sciences.

Measurement Units, Standards, and SI Basics

measurement-units-standards-and-si-basics

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units and standards of measurement

Measurement units, standards, and SI basics help scientists describe physical quantities clearly. A unit gives a number meaning, while a standard provides a fixed reference for that measurement. Together, they make results easier to compare and understand. The International System of Units, or SI, is the most common measurement system in science. It uses agreed-upon base units for common quantities. These standards reduce confusion when measurements are shared across labs, classrooms, and...

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position and displacement

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Learn how measurement units, standards, and the SI system give physical quantities clear meaning and make scientific results easier to compare.

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JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

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Measurement Units, Standards, and SI Basics

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