Name: si base units behind measured quantities
Uploaded: 2023-04-30T10:47:58.000Z
Duration: 1 min 14 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Physical Science

PS.1

PS.1.b

Base Quantities and Derived Quantities

Physikalische Größen können in Basisgrößen und abgeleitete Größen unterteilt werden. Basisgrößen können durch ein Messverfahren ausgedrückt werden, und ihre Einheiten werden als Basiseinheiten bezeichnet.
Zum Beispiel wird die Entfernung zwischen zwei Punkten in Metern gemessen. Hier ist die Basisgröße die Entfernung, und die Einheit, die zum Messen verwendet wird, ist der Meter, der die Basiseinheit ist.
Die physikalischen Größen, die aus den Kombinationen von Basisgrößen erhalten werden, werden als abgeleitete Größen bezeichnet, und die Einheiten, die zur Definition dieser Größen verwendet werden, werden als abgeleitete Einheiten bezeichnet.
Zum Beispiel ist die Geschwindigkeit eines fahrenden Autos von einem Punkt zum anderen definiert als die zurückgelegte Strecke geteilt durch die Fahrzeit. Dabei ist die Geschwindigkeit eine abgeleitete Größe, die sich aus den Basisgrößen Distanz und Zeit ergibt.
Die Einheit der Geschwindigkeit ist Meter pro Sekunde, die abgeleitete Einheit aus den Basiseinheiten, Metern und Sekunden. Alle abgeleiteten Größen und abgeleiteten Einheiten werden aus Basismengen bzw. Basiseinheiten definiert.

basisgrößen und abgeleitete größen

In jedem Einheitensystem müssen die Einheiten für einige physikalische Größen durch einen Messprozess festgelegt werden. Diese Messungen sind die Basisgrößen des Systems und ihre Einheiten sind die Basiseinheiten des Systems. Die algebraischen Kombinationen der Basiswerte können dann verwendet werden, um alle anderen physikalischen Größen auszudrücken. Jede dieser physikalischen Größen wird dann als abgeleitete Größe bezeichnet, wobei jede Einheit als abgeleitete Einheit bezeichnet wird.

Die International Organization for Standardization empfiehlt die Verwendung von sieben Basisgrößen, die das Internationale System der Größen (ISQ) bilden. Alle anderen physikalischen Größen können als Kombinationen dieser sieben Basisphysikalischen Größen ausgedrückt werden. Zum Beispiel wird in der Geometrie das Konzept des Flächeninhalts immer als Produkt von zwei Längen berechnet. Fläche ist daher eine abgeleitete Größe, die in Bezug auf SI-Basiseinheiten in Quadratmetern ausgedrückt werden kann. Die Dichte wird hingegen als Masse durch Volumen definiert, was in Bezug auf SI-Basiseinheiten in Kilogramm pro Kubikmeter (kg/m3) ausgedrückt wird. Zusammenfassend können alle physikalischen Größen aus den sieben Basisgrößen abgeleitet werden, und die Einheiten aller physikalischen Größen können aus den sieben SI-Basiseinheiten abgeleitet werden.

Dieser Text ist angepasst von <a href="https://openstax.org/books/university-physics-volume-1/pages/1-2-units-and-standards">Openstax University Physics Volume 1, Abschnitt 1.2 Einheiten und Standards.</a>

Basisgrößen und Abgeleitete Größen

In jedem Einheitensystem müssen die Einheiten für bestimmte physikalische Größen durch ein Messverfahren angegeben werden. Bei diesen Maßen handelt es sich um die Basisgrößen ...

Education

Lehre

JoVE Core

Physics

Physik

Unit 1

Einheit 1

Units, Dimensions, and Measurements

Einheiten, Dimensionen und Messungen

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

si base units behind measured quantities

SI base units are the starting point for measuring physical quantities. In any system of units, some quantities must be defined through direct measurement. These are called base quantities, and their units are base units.

Other physical quantities are built from these base values by algebraic combinations. These are called derived quantities, and their units are derived units. For example, area comes from two lengths multiplied together. It is a derived quantity and is written in SI base units as square meters.

The International Organization for Standardization recommends seven base quantities. Together, they make up the International System of Quantities, or ISQ. Every other physical quantity can be expressed as a combination of these seven base physical quantities. Density is one example. It is mass divided by volume and is written in SI base units as kilograms per cubic meter, or kg/m^3.

In this way, the seven SI base units provide the foundation for every other unit. Once the base quantities are known, derived quantities and derived units can be written from them. This idea helps connect common measurements like area and density to the full SI system.

SI Base Units Behind Measured Quantities

the scope of physics

How Physics Shapes Science and Technology

Physics studies the interactions of energy, matter, space, and time. It looks for the basic mechanisms that explain natural phenomena. The word physics comes from the Greek word physis, which means nature. Physics helps us understand the natural world at its most fundamental level. It relies on quantitative laws, or rules written in numbers and measurements, to describe how things behave. That approach can also help other fields improve the limits of current technology. Physics matters in...

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models, theories, and laws

Scientific Models, Theories, and Laws

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units and standards of measurement

SI Units for Physical Quantities

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estimation of the physical quantities

Fermi Estimation for Physical Quantities

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base quantities and derived quantities

SI base units are the starting point for measuring physical quantities. In any system of units, some quantities must be defined through direct measurement. These are called base quantities, and their units are base units. Other physical quantities are built from these base values by algebraic combinations. These are called derived quantities, and their units are derived units. For example, area comes from two lengths multiplied together. It is a derived quantity and is written in SI base units...

conversion of units

Unit Conversion Steps and Real-World Errors

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accuracy and precision

Repeated Measurements in Science

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random and systematic errors

How Measurement Errors Affect Results

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rules for significant figures

Measurement Precision and Significant Figures

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significant figures in calculations

Rounding Rules for Significant Figures

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dimensional analysis

Dimensional Checks in Physics Equations

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problem solving: dimensional analysis

Dimensional Checks for Physics Equations

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Physics Problem Solving: Strategy to Check

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key terms and concepts

Learn how base quantities, base units, derived quantities, and derived units connect in the SI system, with examples like area and density.

SI Base Units Behind Measured Quantities | JoVE K12

physics

JoVE Core Physics introduces the theory and application of fundamental physics topics, including kinematics, dynamics, fluid mechanics, statics, waves, and acoustics, with concise and easy-to-understand animated videos. Additionally, the scientist-in-action videos demonstrate the application of related concepts in classical and original research experiments performed in today's laboratories worldwide.

PH.1

PH.1.b

Texas Essential Knowledge and Skills

High School

Chemistry

CHEM.1

CHEM.1.E

PHYS.1

PHYS.1.E

Chemistry and Physics

IPC.1

IPC.1.E

Scientific Method

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Decision Making: P-value Method

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Decision Making: Traditional Method

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empirical-method-to-interpret-standard-deviation

Empirical Method to Interpret Standard Deviation

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Solving Problems in Physics

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The student will demonstrate an understanding of scientific and engineering practices by asking questions and defining problems
• ask questions that require empirical evidence to answer
• develop hypotheses indicating relationships between independent and dependent variables
• offer simple solutions to design problems

PS.1.a

What is an Experiment?

An experiment is a planned activity carried out under controlled conditions. The purpose of an experiment is to investigate the relationship between two ...

Study Design in Statistics

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Observational Studies

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Experimental Designs

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Randomized Experiments

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Crossover Experiments

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Blinding

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Clinical Trials

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Data Collection by Observations

Data collection refers to a systematic way of obtaining, observing, measuring, and analyzing accurate information. Observational studies are one of the ...

Data Collection by Survey

The systematic method of obtaining and analyzing accurate information of a population is called data collection. A survey is a standard method of data ...

Units and Standards of Measurement

A physical quantity is defined either by specifying its measurement method or by stating how it is calculated from other measurements. For example, ...

Estimation of the Physical Quantities

On many occasions, physicists, other scientists, and engineers need to make estimates of a particular quantity. These are sometimes referred to as ...

In any system of units, the units for some physical quantities must be specified through a measurement process. These measurements are the base quantities ...

Conversion of Units

Sometimes, there is a need to convert from one unit to another one. For instance, reading a cookbook in which quantities are expressed in units of liters ...

The student will demonstrate an understanding of scientific and engineering practices by planning and carrying out investigations
• independently and collaboratively plan and conduct observational and experimental investigations; identify variables, constants, and controls where appropriate and include the safe use of chemicals and equipment
• evaluate the accuracy of various methods for collecting data
• take metric measurements using appropriate tools and technologies
• apply scientific ideas or principles to design, construct, and/or test a design of an object, tool, process or system

Review and Preview

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What is a Frequency Distribution

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Ogive Graph

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Histogram

The histogram is a graphical representation in the x-y form of data distribution in a data set. The horizontal x-axis is labeled with what the data ...

Relative Frequency Histogram

The relative frequency depicts the proportion of data points that have each value. The frequency tells the number of data points that have each value. ...

Scatter Plot

The most common and easiest way to display the relationship between two variables, x and y, is a scatter plot. A scatter plot shows the direction of a ...

Time-Series Graph

A time-series graph is a line graph with repeated measurements taken at successive intervals of time. It is also called a time series chart. To construct ...

Bar Graph

A bar graph is also called a bar chart and consists of bars that are separated from each other. It either uses horizontal or vertical bars to show ...

Multiple Bar Graph

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Pareto Chart

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Pie Chart

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What is Variation?

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Range

The range is one of the measures of variation. It can be defined as the difference between a dataset&#39;s highest and lowest values. For example, in the ...

Standard Deviation

The most commonly used measure of variation is the standard deviation. It is a numerical value measuring how far data values are from their mean. The ...

Calculating Standard Deviation

The standard deviation is the most common measure of variation. It is a value that tells us how far a data value is from the mean value in a dataset. ...

Variance

&#160;The deviations show how spread out the data are about the mean. A positive deviation occurs when the data value exceeds the mean, whereas a negative ...

Coefficient of Variation

The coefficient of variation measures the dispersion of the data points or distribution around the mean. Using the coefficient of variation, we can ...

Contingency Table

A contingency table provides a way of portraying data that can facilitate calculating probabilities. It is a method of displaying a frequency distribution ...

Statistical Analysis: Overview

An analysis is usually conducted by replicated sampling or repeated measurements on the same sample. This leads to scattered results rather than a single ...

The student will demonstrate an understanding of scientific and engineering practices by pnterpreting, analyzing, and evaluating data
• construct and interpret data tables showing independent and dependent variables, repeated trials, and means
• construct, analyze, and interpret graphical displays of data and consider limitations of data analysis
• apply mathematical concepts and processes to scientific questions
• use data to evaluate and refine design solutions to best meet criteria

PS.1.c

Models, Theories, and Laws

Scientists frequently use models to help them comprehend a specific collection of phenomena. In physics, a model is a condensed version of a physical ...

Inductive Reasoning

Inductive reasoning is a form of logical thinking that uses related observations to arrive at a general conclusion. It is uncertain and operates in ...

Deductive Reasoning

Deductive reasoning, or deduction, is the type of logic used in hypothesis-based science. In deductive reasoning, the pattern of thinking moves in the ...

The student will demonstrate an understanding of scientific and engineering practices by constructing and critiquing conclusions and explanations
• construct scientific explanations based on valid and reliable evidence obtained from sources (including the students' own investigations)
• construct arguments supported by empirical evidence and scientific reasoning
• generate and compare multiple solutions to problems based on how well they meet the criteria and constraints
• differentiate between a scientific hypothesis, theory, and law

PS.1.d

The student will demonstrate an understanding of scientific and engineering practices by developing and using models
• construct, develop, and use models and simulations to illustrate and/or explain observable and unobservable phenomena
• evaluate limitations of models

PS.1.e

The Scientific Method

Chemistry is an empirical science. Scientists often pose questions to understand the chemistry in everyday life and seek answers to these questions. To ...

The student will demonstrate an understanding of scientific and engineering practices by obtaining, evaluating, and communicating information
• read scientific texts, including those adapted for classroom use, to determine the central idea and/or obtain scientific and/or technical information
• gather, read, and synthesize information from multiple appropriate sources and assess the credibility, accuracy, and possible bias of each publication
• construct, use, and/or present an oral and written argument supported by empirical evidence and scientific reasoning

PS.1.f

SI Base Units Behind Measured Quantities

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