Name: mechanics in physics and engineering
Uploaded: 2023-09-22T11:49:18.000Z
Duration: 1 min 28 s
Channel: JoVE

K12 Standards

Arizona Science Standards

High School

Physical Science

HS.P3

HS.P3U2.7

An Introduction to Mechanics

מכניקה היא ענף במדע הפיזיקלי העוסק בחקר מצבו של אובייקט במנוחה או בתנועה תחת פעולת כוחות.
T מסווג בדרך כלל כמכניקת גוף נוקשה, מכניקת גוף מעוותת ומכניקת זורמים.
מכניקת גוף נוקשה חוקרת את אותם אובייקטים שבהם העיוות זניח תחת פעולת כוחות.
זה יכול להיות מסועף לתוך סטטיקה ודינמיקה. סטטיקה עוסקת במצב של אובייקטים במנוחה, בעוד דינמיקה עוסקת באובייקטים בתנועה.
הדינמיקה מחולקת עוד יותר לקינמטיקה וקינטיקה, שם הכוחות האחראים לתנועה מוזנחים ונחשבים, בהתאמה.
מכניקת גוף מעוותת חוקרת את העיוות של אובייקט תחת פעולת כוחות.
חקר התנועה והכוחות של זורמים נקרא מכניקת זורמים. הוא מסווג עוד יותר נוזלים דחיסים ובלתי דחיסים.
תכנון וניתוח מבנים כגון מבנים, קפיצי עלים במכוניות, ווי מנוף, אקדחי מסמרים פנאומטיים, מערכות בלימה הידראוליות ורובוטים תעשייתיים מבוססים על עקרונות המכניקה.

<ol>
	<li>היבלר, R.C. (2016). מכניקה הנדסית - סטטיקה ודינמיקה. הובוקן, ניו ג'רזי: אולם פירסון פרנטיס. עמ' 3 \u2012 4</li>
	<li>באר, פ"פ; ג'ונסטון, א.ר.; מזורק, ד"ו; קרומוול, פי ג'יי ועצמי, ב. (2019). מכניקה וקטורית למהנדסים - סטטיקה ודינמיקה. ניו יורק: מקגרו-היל. עמ' 2 \u2012 3</li>
	<li>מרים, י"ל; Kraige, L.G. ובולטון, J.N. (2020). מכניקה הנדסית - סטטיקה. הובוקן, ניו ג'רזי: ג'ון ווילי. עמ' 1 \u2012 2</li>
</ol>

מבוא למכניקה

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בני אדם מייצרים ספינות, מקלטים, פירמידות, כלי נשק, ציוד חקלאי ופריטים רבים נוספים מבלי לתעד את התהליך או התיאוריה מאחוריהם במשך מאות שנים. זה יהיה מאתגר לתעד את התפתחות המכניקה ממקורה ועד היום. 


לפי רישומים, ההיסטוריה של המכניקה מתחילה באריסטו (384-322 לפני הספירה). הוא קשר את המכניקה לתיאוריה הפיזיקלית, מתוך כוונה לסינתזה אוניברסלית. 

ניוטון הגדיר את המכניקה כענף במדע הפיזיקלי החוקר את מצבו של עצם במנוחה או בתנועה תחת פעולת כוחות. מכניקה היא תחום בסיסי בפיזיקה עם יישומים משמעותיים בענפים שונים של הנדסה ומדע. לימוד המכניקה חיוני להבנת תנועתם של חפצים יומיומיים, התנהגותם של מכונות והתקנים ותפקודן של מערכות שונות. 

מכניקת גוף נוקשה היא ענף של מכניקה העוסק באובייקטים בהם העיוות זניח בהשפעת כוחות. ניתן לחלק את מכניקת הגוף הנוקשה לענפי הסטטיקה והדינמיקה. סטטיקה עוסקת במצב של עצמים במנוחה, ואילו דינמיקה עוסקת בעצמים בתנועה. הדינמיקה מחולקת עוד יותר לקינמטיקה וקינטיקה, כשהראשון מזניח את הכוחות האחראים לתנועה והאחרון מתחשב בהם. 

מכניקת גוף הניתנת לעיוות, לעומת זאת, מתמקדת בדפורמציה של עצם תחת פעולת כוחות. הבנת ההתנהגות של חומרים, כגון אלה המשמשים בבנייה או בייצור, ותכנון וניתוח של מבנים שונים היא חיונית. 

מכניקת נוזלים היא חקר התנועה והכוחות של נוזלים. זהו תחום עצום, והוא מסווג לנוזלים דחוסים ובלתי ניתנים לדחיסה, בהתאם להתנהגותם. למכניקת נוזלים יש יישומים מעשיים רבים והיא משמשת בתכנון וניתוח מערכות שונות, כגון מערכות הידראוליות או פנאומטיות, מערכות להובלת נוזלים וציוד לעיבוד כימי. 

מבנים ומכונות רבים מתוכננים ומנותחים על סמך עקרונות המכניקה. לדוגמה, התכנון של מבנים, גשרים ומבנים אחרים תלוי בעקרונות של מכניקה כדי להעריך את חוזק החומרים, כוחות הכבידה ותנועת כדור הארץ. עקרונות מכניקה משמשים גם בתכנון של רכיבי רכב, כגון קפיצי עלים ומערכות בלימה הידראולית, ווי מנוף, רובוטים תעשייתיים ותותחי מסמר פנאומטיות.

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בני האדם יצרו ספינות, מקלטים, פירמידות, כלי נשק, ציוד חקלאי ועוד פריטים רבים מבלי לתעד את התהליך או התיאוריה שמאחורי ...

Education

JoVE Core

Mechanical Engineering

הנדסת מכונות

Unit 1

יחידה 1

An Introduction to Statics

מבוא לסטטיקה

KEY TERMS AND CONCEPTS

מונחים ומושגים מרכזיים

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 rest or in motion under the action of forces.

Rigid body mechanics deals with objects that do not deform much when forces act on them. This area is divided into statics and dynamics. Statics studies objects at rest, while dynamics studies objects in motion.

Dynamics is further divided into kinematics and kinetics. Kinematics describes motion without focusing on the forces that cause it. Kinetics includes those forces and explains how they affect motion.

Deformable body mechanics focuses on how objects change shape under force. This is important for understanding materials used in construction and manufacturing. It also helps in the design and analysis of structures.

Fluid mechanics studies the motion of fluids and the forces within them. It is often divided into compressible and incompressible fluids, based on how the fluid behaves. This field is used in hydraulic and pneumatic systems, fluid transportation, and chemical processing equipment.

Principles of mechanics guide the design of many structures and machines. Buildings and bridges are analyzed for material strength, gravity, and earth movement. The same ideas also apply to automobile leaf springs, hydraulic braking systems, crane hooks, industrial robots, and pneumatic nail guns.

Mechanics in Physics and Engineering

an introduction to mechanics

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

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 mechanics explains motion, forces, statics, dynamics, fluids, and material behavior, with real-world examples in structures and machines.

Mechanics in Physics and Engineering | 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

Position and Displacement

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Average Velocity

To calculate the other physical quantities in kinematics, we must introduce the time variable. The time variable allows us not only to state the position ...

Average Acceleration

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Velocity and Position by Graphical Method

Velocity and position can be calculated from the known function of acceleration as a function of time. The total area under the acceleration-time graph ...

Kinematic Equations - I

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Force

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Newton's Laws of Motion

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Newton's First Law: Introduction

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First Law: Particles in One-dimensional Equilibrium

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Newton's Second Law

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Second Law: Motion under Same Force

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Newton's Third Law: Introduction

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Equilibrium and Free-body Diagrams

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Collect, analyze and interpret data regarding the change in motion of an object or system in one dimension, to construct an explanation using Newton’s Laws.

HS.P3U1.6

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Use mathematics and computational thinking to explain how Newton’s laws are used in engineering and technologies to create products to serve human ends.

Mechanics in Physics and Engineering

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