Name: si and customary measurement systems
Uploaded: 2023-09-22T11:49:19.000Z
Duration: 1 min 27 s
Channel: JoVE

길이, 질량 및 시간은 측정을 위한 기본 수량이며 그 단위는 기본 단위라고 합니다.
기본 단위에서 파생된 단위를 파생 단위라고 합니다.
단위 체계는 국제 단위계 또는 SI 단위와 미국 관습 단위 체계로 분류 할 수 있습니다.
SI 단위에서는 미터, 킬로그램 및 초가 기본 단위이고 미국 관습 단위 시스템에서는 피트, 파운드 및 초가 기본 단위입니다.
예를 들어, SI 힘의 단위는 파생 단위인 뉴턴입니다. 초당 1미터의 제곱 비율로 1kg의 질량을 가속하는 데 필요한 힘으로 정의됩니다.
미국 관습 단위 체계에서 질량 단위는 파생 된 단위 인 슬러그입니다. 그것은 1파운드의 힘에 의해 작용할 때 초당 1피트의 제곱으로 가속되는 물질의 양으로 정의됩니다.
한 시스템의 단위는 변환 계수를 사용하여 다른 시스템의 단위로 변환할 수 있습니다.

<ol>
	<li>히벨러, R.C. (2016). Engineering Mechanics \u2012 정역학 및 동역학. 뉴저지 호보켄: 피어슨 프렌티스 홀. 7쪽\u20128</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. 4쪽과 8</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>

측정 단위

Units of Measurement

기계공학은 공학의 가장 오래된 분야 중 하나입니다. 기계 및 기계 시스템의 설계, 분석, 제조를 다룹니다. 정밀하고 정확한 계산을 보장하기 위해 측정 단위가 사용됩니다. 물리량을 표현하고 비교하기 위한 표준 시스템을 제공합니다.
바빌로니아 시스템, 로마 시스템, 이집트 시스템, 올림피아 시스템, 영국 시스템, 인더스 계곡 시스템 등 역사적으로 잘 알려진 다양한 각 나라의 측정 시스템이 있습니다.
국제 단위계(SI)는 기계 공학에서 보편적으로 사용되고, 인정되는 측정 표준입니다. 이는 다른 모든 물리량을 표현하기 위해 결합될 수 있는 몇 가지 기본 단위를 기반으로 합니다.
기본 단위에서 파생된 단위를 파생 단위라고 합니다. 예를 들어, 힘의 SI 단위는 파생 단위인 뉴턴입니다. 이는 1kg의 질량을 초당 1m의 속도로 가속하는 데 필요한 힘으로 정의됩니다.
전 세계적으로 다양한 측정 단위 시스템이 사용됩니다. 국제 단위계(SI) 외에 미국 관습 단위계도 널리 사용되는 또 다른 단위입니다. 미국 관습 단위 체계에서 기본 단위는 피트, 파운드, 초입니다. 길이의 단위는 피트, 질량의 단위는 파운드, 시간의 단위는 초입니다.
미국 관습 단위계에서 질량 단위는 파생 단위인 슬러그입니다. 이는 1파운드의 힘이 작용할 때 초당 1피트씩 가속되는 물질의 양으로 정의됩니다.
많은 국가에서 미국 관세 제도를 지속적으로 활용하고 있기 때문에 다양한 비교 단위 간의 관계도 발전해 왔습니다. 예를 들어 1미터는 3,280피트와 같습니다. 파생 단위도 표준 세트마다 다릅니다. 예를 들어, SI 체계에서는 힘의 단위로 뉴턴을 사용하지만 미국 관습 체계에서는 파운드를 사용합니다.
측정 단위는 정밀하고 정확한 측정을 가능하게 하기 때문에 기계 공학에서 필수적입니다. 엔지니어는 이러한 장치를 사용하여 기계 및 기계 시스템을 설계 및 분석하고, 기계 구성요소의 하중, 응력 및 변형을 추정하고, 다양한 작동 조건에서 기계의 동작을 예측합니다.

기계 공학은 가장 오래된 공학 분야 중 하나입니다. 그것은 설계, 분석 및 제조 기계 및 기계를 다룹니다 ...

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 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 System of Units, or SI, is the widely recognized standard used in mechanical engineering.

The SI system is built from base units. These base units can be combined to describe other physical quantities, which are called derived units. For example, the SI unit of force is the Newton. One Newton is the force needed to accelerate one kilogram of mass at one meter per second squared.

Another common system is the U.S. Customary System of Units. Its base units are the foot, the pound, and the second. In this system, length is measured in feet, mass is measured in pounds, and time is measured in seconds. The slug is the derived unit used for mass in this system, and it is defined by the amount of matter accelerated by one foot per second squared under a force of one pound.

Because many countries still use the U.S. Customary System, conversion relationships are important. For example, one meter equals 3,280 feet. Derived units also differ between systems. SI uses the Newton for force, while the U.S. Customary System uses the pound. Engineers use these units to estimate loads, stresses, and deformations, and to predict how machines behave under different operating conditions.

SI and Customary Measurement Systems

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...

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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

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

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...

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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...

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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

Explore SI and U.S. Customary units, base and derived units, and how engineers use measurement systems to calculate force, loads, and machine behavior.

SI and Customary Measurement Systems | 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

SI and Customary Measurement Systems

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