Name: si units and metric prefixes
Uploaded: 2023-09-22T11:49:19.000Z
Duration: 1 min 29 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Specialised Topic in Science

112.51.c.1.

112.51.c.1.E.

International System of Units

국제 단위계는 전 세계적으로 널리 받아들여지며 기본 단위는 미터, 킬로그램 및 초입니다. 이러한 단위는 절대 단위이며 해당 값은 위치에 따라 변경되지 않습니다.
접두사는 더 큰 수량과 더 작은 수량을 정의하는 데 사용됩니다. 밀리, 마이크로 및 나노는 더 적은 양을 나타내는 데 사용되며 킬로, 메가 및 기가는 더 많은 양을 나타내는 데 사용됩니다.
그러나 기본 단위 중에서 킬로그램은 접두사로 정의된 유일한 기본 단위입니다.
단위와 접두사를 표현하는 동안 몇 가지 규칙을 따라야 합니다. 첫째, 점은 복합 단위에서 단위를 구별하는 데 사용됩니다.
둘째, 접두사는 분모에서 피하고 복합 단위의 분자로만 표현됩니다.
셋째, 접두사가 있는 단위의 지수 전력은 접두사와 해당 단위에 적용되며, 마지막으로 결과는 단일 접두사를 사용하여 표시됩니다.
미터법과 달리 SI는 deca 또는 centi의 배수를 사용하지 않습니다.

<ol>
	<li>히벨러, R.C. (2016). Engineering Mechanics \u2012 정역학 및 동역학. 뉴저지 호보켄: 피어슨 프렌티스 홀. 9쪽\u201210</li>
	<li>맥주, F.P.; 존스턴, ER; 마주렉, D.F; 크롬웰, PJ 및 셀프, BP (2019). 엔지니어를 위한 벡터 역학 \u2012 Statics and Dynamics. 뉴욕 : McGraw-Hill. 5쪽과 7</li>쪽
	<li>메리암, J.L.; Kraige, L.G. 및 Bolton, J.N. (2020). 엔지니어링 역학 \u2012 정역학. 뉴저지 호보켄: 존 와일리. 7, 8쪽</li>
</ol>

국제 단위계

SI 시스템으로 알려진 국제 단위계는 전 세계적으로 인정받고 사용되는 보편적인 측정 시스템입니다. SI 시스템은 절대적으로 간주되는 세 가지 기본 단위 세트를 기반으로 하며 해당 값은 위치에 따라 변경되지 않습니다. 기본 단위는 미터, 킬로그램, 초입니다.
접두사는 SI 시스템에서 더 큰 수량과 더 작은 수량을 모두 정의하는 데 사용됩니다. 예를 들어, milli, micro 및 nano는 더 작은 수량을 정의하는 반면 kilo, mega 및 giga는 더 큰 수량을 정의하는 데 사용됩니다. 킬로그램은 SI 시스템의 기본 단위 중 접두어로 정의되는 유일한 기본 단위입니다.
단위와 접두어를 표현하는 데에는 몇 가지 규칙을 따라야 합니다. 첫째, 점은 단위를 복합 단위로 구별하는 데 사용됩니다. 둘째, 분모에는 접두사를 피하고 복합단위의 분자에만 표현한다. 셋째, 접두사가 있는 단위의 지수 거듭제곱은 접두사와 해당 단위에 적용됩니다. 마지막으로 결과는 단일 접두사를 사용하여 표시됩니다.
미터법과 달리 SI 체계는 데카나 센티의 배수를 사용하지 않는다는 점에 유의해야 합니다. SI 시스템의 접두사는 10의 거듭제곱을 기반으로 하며 기본 단위에는 접두사가 없습니다. SI 단위는 보편적 시스템을 활용하여 과학적 측정을 단순화하고 표준화하기 위한 것입니다.
SI 시스템이 전 세계적으로 사용되는 주요 이유 중 하나는 측정의 정확성과 정밀도입니다. 가장 미량 및 대량 수량도 기본 단위와 접두사를 사용하여 정확하게 정량화할 수 있습니다.
SI 시스템의 기본 길이 단위는 미터로, 특정 시간 동안 빛이 진공 상태에서 이동하는 거리로 정의됩니다. 센티미터, 킬로미터, 밀리미터와 같은 다른 측정값은 접두사 시스템을 사용하여 미터에서 파생될 수 있습니다.
SI 시스템의 기본 질량 단위는 킬로그램이며 국제 킬로그램 원기라고 알려진 일련의 기초 물체의 질량으로 정의됩니다. 그램, 밀리그램과 같은 다른 질량 측정값은 접두사 시스템을 사용하여 킬로그램에서 파생될 수 있습니다.
SI 시스템의 기본 시간 단위는 초로, 세슘-133 원자의 에너지 준위 사이의 특정 전이와 관련된 방사선의 9,192,631,770주기의 지속 시간으로 정의됩니다. 초부터 분, 시간과 같은 다른 시간 측정값은 접두사 시스템을 사용하여 파생될 수 있습니다.
이러한 단위 외에도 기본 측정 단위로 4가지가 더 정의되어 있습니다. 암페어, 켈빈, 몰, 칸델라입니다.

SI 시스템으로 알려진 국제 단위계는 전 세계적으로 인정되고 사용되는 보편적으로 인정되는 측정 시스템입니다. SI 시스템은 ...

Education

교육

JoVE Core

Mechanical Engineering

기계공학

Unit 1

제1단원

An Introduction to Statics

정역학 입문

KEY TERMS AND CONCEPTS

주요 용어 및 개념

si units and metric prefixes

SI units and metric prefixes provide a standard way to measure size, mass, and time. The International System of Units, or SI system, is used worldwide because it gives scientists a common language for measurement. Its values do not change with location, which helps keep results consistent.

The SI system is built on three base units: meter, kilogram, and second. These are the core units for length, mass, and time. The kilogram is the only base unit that already includes a prefix.

Prefixes make it easy to express very large or very small values. Milli, micro, and nano represent smaller quantities. Kilo, mega, and giga represent larger quantities. SI prefixes are based on powers of ten, and the base unit has no prefix.

Several rules apply when writing SI units. Dots are used to separate units in composite units. A prefix should not appear in the denominator, only in the numerator. If a unit with a prefix is raised to a power, the power applies to both the prefix and the unit. The final answer should use just one prefix. Unlike the metric system, SI does not use deca or centi.

SI units help simplify and standardize scientific measurements. They also improve accuracy and precision, even for very small or very large quantities. The meter is defined as the distance light travels in a vacuum during a specific time frame. Other length units, such as centimeter, kilometer, and millimeter, come from the meter.

The kilogram is the SI base unit of mass. It was defined as the mass of a set of foundational objects called the International Prototype of the Kilogram. Grams and milligrams are derived from the kilogram. The second is the SI base unit of time and is defined by 9,192,631,770 cycles of radiation from a specific transition in cesium-133. Minutes and hours can be derived from the second. Four more fundamental units are also part of SI: ampere, Kelvin, mole, and candela.

SI Units and Metric Prefixes

an introduction to mechanics

Mechanics in Physics and Engineering

Mechanics is a key branch of physics that explains how objects stay at rest or move when forces act on them. It also has major uses in engineering and science. The topic helps students understand everyday motion, machine behavior, and the way many systems work. The recorded history of mechanics begins with Aristotle, who lived from 384 to 322 BC. He linked mechanics with physical theory and looked for a broad universal explanation. Later, Newton defined mechanics as the study of objects at...

basic concept

Fundamental Quantities in Engineering Mechanics

Engineering mechanics begins with four basic quantities: length, time, mass, and force. These ideas help describe how objects move and how they respond to loads. They also support many other engineering fields. Length measures the distance traveled by an object. Engineers describe this distance with coordinates relative to a reference point. Length is also useful for showing the geometry of physical systems. Time measures the succession of an event. A bus traveling from city X to city Y is a...

newton's law of motion

Newton's Laws and Everyday Motion

Newton's laws explain everyday motion and the forces that change it. These three laws describe why objects move, stay still, or speed up. They also show how force and mass affect motion. Newton's first law is the law of inertia. It says an object at rest stays at rest, and an object in motion keeps moving at a constant speed and direction unless an external force acts on it. A sliding box that slows down on its own is a good example. In that case, friction is the net external force that works...

newton's law of gravitational attraction

Gravity Between Masses and Distance

Newton’s law of gravitational attraction describes how gravity acts between two objects. Sir Isaac Newton built this law from empirical evidence and inductive reasoning. He published it in Philosophiae Naturalis Principia Mathematica, or the Principia, on July 5, 1687. The law says that the gravitational force between any two objects depends on their masses and their distance apart. The force is proportional to mass and inversely proportional to the square of the distance between the objects.

units of measurement

SI and Customary Measurement Systems

Mechanical engineering depends on units of measurement for precise and accurate calculations. These units give engineers a standard way to express and compare physical quantities. They are essential when designing and analyzing machines and mechanical systems. Many historical measurement systems have been used over time. Examples include the Babylonian system, the Roman system, the Egyptian system, the Olympian system, the British system, and the Indus Valley system. Today, the International...

international system of units

SI units and metric prefixes provide a standard way to measure size, mass, and time. The International System of Units, or SI system, is used worldwide because it gives scientists a common language for measurement. Its values do not change with location, which helps keep results consistent. The SI system is built on three base units: meter, kilogram, and second. These are the core units for length, mass, and time. The kilogram is the only base unit that already includes a prefix. Prefixes...

numerical calculations

Engineering Notation and Significant Figures

Numerical calculations in engineering depend on clear values, correct units, and careful rounding. Presenting the answer is an important part of engineering practice, so numerically accurate results are preferred. Handheld calculators and computers are often used because they help produce accurate answers. Problems can be solved in several ways. Solving algebraic symbols by hand is common, and the graphical method is often preferred in some cases. Computers are especially useful when many...

accuracy, limits, and approximation

Accuracy and Approximation in Calculations

Accuracy and approximation are important in calculations, especially in engineering. Accuracy means how close a measured value is to the true or actual value. Repeated measurements are often used in engineering mechanics to help make results more precise and accurate. The accuracy of a solution depends on empirical data and the results from different calculations or measurements. A cylindrical container filled with liquid is a simple example. Its volume can be found from the measured...

dimensional analysis

Using Dimensions to Check Physics Equations

Dimensional analysis is a useful way to check physics and engineering equations. It works by writing physical quantities in terms of basic dimensions such as mass, length, and time. Quantities like velocity, acceleration, and force are derived from these basic dimensions. This method helps compare measurements even when the units are different. It also checks whether an equation is dimensionally homogeneous. That means the powers of the fundamental dimensions must match on both sides of the...

problem solving in statics

Statics Problem-Solving Steps for Beams

Statics problem-solving uses a step-by-step method to analyze bodies in equilibrium, especially beams. It is an important part of physics and engineering because the goal is to find practical and accurate answers for real situations. The process usually starts with a physical situation and then turns it into a mathematical model. That model often needs approximations and assumptions. Very small distances can be ignored when they are much smaller than the main dimensions, such as beam width...

key terms and concepts

Learn how SI units use meters, kilograms, seconds, and metric prefixes to measure length, mass, and time with accuracy and consistency.

SI Units and Metric Prefixes | JoVE K12

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.

mechanical engineering

Physics

PHYS.1

PHYS.1.E

Chemistry and Physics

IPC.1

IPC.1.E

The Scientific Method

The scientific method is a detailed, empirical problem-solving process used by biologists and other scientists. This iterative approach involves ...

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 ...

Correlation and Causation

Correlation and CausationStatistical tests can calculate whether there is a relationship, or correlation, between independent and dependent variables. A ...

Ask questions and define problems related to specialized topics of study based on observations or information from text, phenomena, models, or investigations;

112.51.c.1.A.

Scientific Method

The scientific method is used to solve problems and explain phenomena. The development of the scientific method coincided with changes in philosophy ...

Demonstrating the Scientific Method with Tree Branches
ExpandObtain branches containing a few dozen typical leaves from five different local tree species. ...

Observation and Background Research
ExpandNOTE: The first two steps in the scientific process involve studying and observing natural phenomena of ...

Problem-Solving

A problem-solving strategy is a plan of action used to find a solution. It involves trial and error, algorithms, heuristics, and insights. Effective ...

Problem Definition

Problem definition is the initial and the most essential step in research.
The researcher identifies and explains the specific issue or gap to be ...

Apply science practices related to specialized topics of study to plan and conduct investigations or use engineering practices to design solutions to problems;

112.51.c.1.B.

Proper Personal Protective Equipment

Robert M. Rioux &#38; William A Elliott, Pennsylvania State University, University Park, PA
Hazards are many and varied in the laboratory, but the right ...

Emergency Eyewash and Shower Stations

Robert M. Rioux, Pennsylvania State University, University Park, PA
The Occupational Safety and Health Administration (OSHA) mandates that an emergency ...

Electrical Safety

Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Among the many hazards present in the laboratory, electrical ...

Working with Centrifuges

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Earth's gravitational force is capable of separating ...

Working with Hot and Cold Sources

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Working with extreme temperatures, both high and low, ...

guidelines-in-case-of-a-laboratory-emergency

Guidelines in Case of a Laboratory Emergency

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
The most common laboratory emergencies include chemical spills, ...

chemical-storage-categories-hazards-and-compatibilities

Chemical Storage: Categories, Hazards And Compatibilities

Source: Robert M. Rioux &amp; Taslima A. Zaman, Pennsylvania State University, University Park, PA
While the use of various chemicals in experimental ...

Safe Handling of Mineral Acids

Source: Robert M. Rioux &#38; Taslima A. Zaman, Pennsylvania State University, University Park, PA
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Handling Chemical Spills

Source: Robert M. Rioux &#38; Taslima Zaman, Pennsylvania State University, University Park, PA
Since chemicals are commonly used for laboratory research ...

Proper Use of Autoclaves

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
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Fume Hoods and Laminar Flow Cabinets

Robert M. Rioux &amp; William A. Elliott, Pennsylvania State University, University Park, PA
Fume hoods and laminar flow cabinets are engineering controls ...

Decontamination for Laboratory Biosafety

Robert M. Rioux and Zhifeng Chen, Pennsylvania State University, University Park, PA
Decontamination is essential for laboratory biosafety, as the ...

Proper Waste Disposal

Robert M. Rioux and Taslima A. Zaman, Pennsylvania State University, Pennsylvania, PA

Users are responsible for the proper disposal of the waste ...

Use appropriate safety equipment and practices during laboratory, classroom, and field investigations as outlined in Texas Education Agency-approved safety standards;

112.51.c.1.C.

Common Lab Glassware and Uses

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
Glassware is a regular appearance in the professional ...

Lab Techniques

Measurement Accuracy
The ability to repeat an experiment and get the same results, or reproducibility, is essential in scientific research. However, ...

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Preparation of LaboratoryExpand
	Here we show the laboratory preparation for 10 students ...

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Determining the Density of an EggExpand
	Density is a measure of how compact a substance or ...

Proper Lab Notebook Keeping

Organic Lab Notebook Keeping
Record keeping is a vital skill in science and organic chemistry labs. Without proper notes, descriptions, quantities, or ...

Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA

	Preparation of the LaboratoryExpand
	Here, we show the laboratory preparation ...

Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA

	Nitration of Methyl BenzoateExpand
	From this lab onward, ...

Use tools appropriate to the specialized topic of study;

112.51.c.1.D.

SI Units: 2019 Redefinition

Measurement is integral to analytical chemistry. Each record comprises a number &#8211; denoting the magnitude&#160; &#8211; and the unit &#8211; a ...

The International System of Units, known as the SI system, is a universally accepted measurement system recognized and used worldwide. The SI system is ...

Measurement: Standard Units

Every measurement provides three kinds of information: the size or magnitude of the measurement (a number), a standard of comparison for the measurement ...

Measurement: Derived Units

The International System of Units or SI system, by international agreement, has fixed measurement units for seven fundamental properties: length, mass, ...

Collect quantitative data using the International System of Units (SI) or qualitative data as evidence as appropriate to the specialized topic of study;

Review and Preview

Data are individual items of information obtained from a population or sample. Data may be classified as qualitative (categorical), quantitative ...

What is a Frequency Distribution

A frequency is the number of times a value of the data occurs. The sum of all the frequency values represents the total number of students included in the ...

Cumulative Frequency Distribution

A cumulative frequency distribution is another type of frequency distribution. Instead of reporting how many data values fall in some classes, it reports ...

Ogive Graph

An ogive graph is sometimes called a cumulative frequency polygon. It is one type of frequency polygon that shows cumulative frequency. In other words, ...

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

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Bar Graph

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Multiple Bar Graph

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Pareto Chart

A Pareto chart is a bar graph or a combination of both line and bar graphs. The bar lengths represent the individual values or the frequency, while the ...

Pie Chart

A pie chart (or a pie graph) is a circular graphical chart or a pictorial representation of categorical data. It is divided into slices of pie each ...

Organize quantitative or qualitative data using representations appropriate to the specialized topic of study such as scatter plots, line graphs, bar graphs, charts, data tables, diagrams, scientific drawings, and student-prepared models;

112.51.c.1.F.

Modeling and Similitude

A scaled model of a dam is tested in a controlled environment to observe how it will manage water flow, turbulence, and pressure.
This setup predicts the ...

Typical Model Studies

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...

design-example-creating-a-hydraulic-model-of-a-dam-spillway

Design Example: Creating a Hydraulic Model of a Dam Spillway

A hydraulic model of a dam spillway is often created by scaling down the design, typically to a 1:15 ratio, to replicate key flow characteristics such as ...

Models, Theories, and Laws

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/files/media/science-education/science-education-thumbs/14686.jpg

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The human nervous system translates sensory stimuli into neural impulses, which the brain processes into information as thoughts and memories, forming ...

Molecular Models

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Develop and use models to represent phenomena, systems, processes, or solutions to problems as appropriate to the specialized topic of study; and

112.51.c.1.G.

Scientific Laws and Theories

Scientific Laws

In science, a law is defined as a concise, verbal or mathematical, statement that summarizes a vast number of experimental observations. ...

Distinguish among scientific hypotheses, theories, and laws as appropriate to the specialized topic of study.

112.51.c.1.H.

Identify advantages and limitations of models such as their size, scale, properties, and materials as appropriate to the specialized topic of study;

112.51.c.2.A.

Introduction to Statistics

The science of statistics involves collecting, analyzing, interpreting, and presenting data. The method of collecting, organizing, and summarizing data is ...

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 ...

systematic-error-methodological-and-sampling-errors

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Systematic errors, depending on their source, are of four types &#8211; sampling, instrumental, method, and personal errors.
Sampling errors occur due to ...

Random Error

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Since these errors can neither be predicted nor ...

types-of-errors-detection-and-minimization

Types of Errors: Detection and Minimization

Error is the deflection of an obtained result from the expected or true results of an experiment. This happens due to the uncertainty associated with the ...

Realism in Experimentation

Source: Laboratories of Gary Lewandowski, Dave Strohmetz, and Natalie Ciarocco&#8212;Monmouth University

In an ideal world researchers would conduct ...

Bias

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Ethics in Research

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Analyze data appropriate to the specialized topic of study by identifying significant statistical features, patterns, sources of error, and limitations;

112.51.c.2.B.

Scientific and engineering practices. The student, for at least 40% of instructional time, asks questions, identifies problems, and plans and safely conducts classroom, laboratory, and field investigations to explain phenomena or design solutions using appropriate tools and models. The student is expected to:

SI Units and Metric Prefixes

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