Name: newton's first law and inertia
Uploaded: 2023-04-30T10:53:06.000Z
Duration: 1 min 17 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Physics

motion-and-stability-forces-and-interactions

Motion and Stability- Forces and Interactions

PS.Phy.2.2

Newton's First Law: Introduction

Avant Galilée et Newton, les scientifiques croyaient depuis 2000 ans que les objets ont une tendance naturelle à s’immobiliser s’ils sont laissés seuls.
De plus, une force constante est nécessaire pour les maintenir en mouvement.
Galilée a réfuté cette idée avec une expérience de pensée utilisant une boule de bronze qui est roulée sur des plans lisses à double inclinaison.
Une balle roulée du premier plan monte à la même hauteur sur le deuxième plan.
Si le deuxième plan a un angle d’inclinaison plus petit, la balle se déplace sur une plus grande distance pour atteindre la même hauteur.
Si le deuxième plan est horizontal, la balle doit continuer à bouger indéfiniment pour atteindre la même hauteur.
Galilée a conclu que la force n’est pas nécessaire pour maintenir un corps en mouvement.
Newton a résumé ces observations et d’autres en trois lois du mouvement qui sont fondamentales pour la mécanique.
La première loi stipule que tout objet reste stationnaire ou sous une vitesse constante à moins qu’il ne soit soumis à une force externe nette.

Aucun conflit d’intérêts n’a été déclaré.

la première loi de newton : introduction

Le mouvement attire notre attention. Le mouvement lui-même peut être beau et nous fait nous émerveiller devant les forces nécessaires pour créer des événements spectaculaires, tels que celui d'un dauphin qui saute hors de l'eau, le vol d'un oiseau ou l'orbite d'un satellite. L'étude du mouvement est la cinématique, mais la cinématique décrit uniquement la manière dont les objets se déplacent - leur vélocité et leur accélération. La dynamique prend en compte les forces qui influencent le mouvement des objets et des systèmes en mouvement. Les lois du mouvement de Newton sont le fondement de la dynamique. Ces lois fournissent des exemples de l'étendue et de la simplicité des principes selon lesquels la nature fonctionne. Ce sont aussi des lois universelles, car elles s'appliquent à des situations similaires sur Terre et dans l'espace. Les lois du mouvement d'Isaac Newton (1642-1727 ap. J.-C.) ne sont qu'un aspect du travail monumental qui l'a rendu légendaire. Le développement des lois de Newton marque la transition de la Renaissance à l'ère moderne. Cette transition a été caractérisée par un changement révolutionnaire dans la façon dont les gens pensaient à l'univers physique. Pendant des siècles, les philosophes naturels avaient débattu de la nature de l'univers principalement sur la base de certaines règles de logique, en accordant une grande importance aux pensées des anciens philosophes classiques tels qu'Aristote (384-322 av. J.-C.). Parmi les nombreux grands penseurs qui ont contribué à ce changement, il y avait Newton et Galilée.

Galilée (1564-1642 ap. J.-C.) a contribué à la formation de ce qu'on appelle aujourd'hui la première loi du mouvement de Newton. Newton a utilisé le travail de ses prédécesseurs, ce qui lui a permis de développer les lois du mouvement, de découvrir la loi de la gravité, d'inventer le calcul infinitésimal et de faire de grandes contributions aux théories de la lumière et de la couleur. Étonnamment, bon nombre de ces avancées ont été réalisées par Newton qui travaillait seul, sans bénéficier des interactions entre pairs qui ont lieu entre les scientifiques d'aujourd'hui.

La première loi du mouvement de Newton suggère qu'un corps reste dans le même état, que ce soit au repos ou en mouvement (se déplaçant avec une vélocité constante), jusqu'à ce qu'une force externe soit appliquée. Notez l'expression « vélocité constante » ; cela signifie que le corps maintient une trajectoire le long d'une ligne droite, car ni l'amplitude ni la direction du vecteur vélocité ne changent. La première loi de Newton dit qu'il doit y avoir une cause pour tout changement de vélocité (un changement de magnitude ou de direction) pour se produire. Nous pouvons penser à cette loi comme préservant le statu quo du mouvement. Elle est générale et peut s'appliquer à n'importe quoi, d'un objet glissant sur une table à un satellite en orbite, en passant par le sang pompé par le cœur. Des expériences ont vérifié que tout changement de vélocité (vitesse ou direction) doit être causé par une force externe.

Ce texte est adapté de <a href="https://openstax.org/books/college-physics/pages/4-introduction-to-dynamics-newtons-laws-of-motion">Openstax, College Physics, Section 4.0: Introduction to Dynamics: Newton's Laws of Motion</a> and <a href="https://openstax.org/books/university-physics-volume-1/pages/5-2-newtons-first-law">Openstax University Physics, Section 5.2: Newton's First Law.</a>

La première loi de Newton : introduction

Le mouvement attire notre attention. Le mouvement lui-même peut être beau, nous amenant à nous émerveiller des forces nécessaires pour créer des vues spectaculaires, comme celle d’un ...

Education

Enseignement

JoVE Core

Physique

Unit 1

Unité 1

Newton's Laws of Motion

Les lois du mouvement de Newton

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

newton's first law and inertia

Newton's first law of motion explains inertia and how forces change motion. Motion can be striking to observe, from a dolphin jumping from water to a bird in flight or a satellite moving in orbit. The study of motion is kinematics, which describes velocity and acceleration. Dynamics goes further by examining the forces that affect moving objects and systems.

Newton's laws of motion are the foundation of dynamics. They are simple in form, but they describe a wide range of natural behavior. These laws are also universal, so they apply to similar situations on Earth and in space. Isaac Newton's laws became part of a major shift in science as people moved from older ideas based mainly on logic and classical philosophers such as Aristotle to a more modern view of the physical universe.

Galileo also helped shape what is now called Newton's first law. Newton built on the work of earlier scientists, including Galileo, and used that foundation to develop his laws of motion. His work also led to the law of gravity, calculus, and major advances in light and color. Remarkably, much of this work was done while Newton worked alone, without the peer interaction that scientists have today.

Newton's first law says that an object stays at rest or keeps moving with constant velocity unless an external force acts on it. Constant velocity means the object moves in a straight line with no change in speed or direction. The law states that any change in velocity must have a cause. In that way, it preserves the current state of motion.

This law applies to many situations. A sliding object on a table, a satellite in orbit, and blood pumped from the heart all follow the same rule. Experiments have shown that changes in speed or direction are caused by external forces. That makes Newton's first law a basic idea for understanding motion in physics.

Newton's First Law and Inertia

force

Understanding Force in Motion

Force is a push or pull that acts on an object. It has both magnitude and direction, so force is a vector quantity. In everyday life, force appears when we open a door, walk down a street, lift a fork, or touch a baby's face. Forces also shape matter at the smallest scales. The atoms in our bodies are held together by electrical forces. The nucleus of an atom is held together by nuclear force, which is the strongest force known to us. The study of motion is called kinematics. Kinematics...

types of forces

Contact and Field Forces in Physics

Forces in physics are often grouped as contact forces and field forces. Contact forces happen when objects touch directly. Field forces act without direct physical contact. They come from a field, which is a region of space that can be detected by the force it exerts on a body. Scientists describe four fundamental force fields in nature: gravitational, electromagnetic, strong nuclear, and weak nuclear. The gravitational field gives a body its weight. The electromagnetic field includes static...

newton's first law: introduction

Newton's first law of motion explains inertia and how forces change motion. Motion can be striking to observe, from a dolphin jumping from water to a bird in flight or a satellite moving in orbit. The study of motion is kinematics, which describes velocity and acceleration. Dynamics goes further by examining the forces that affect moving objects and systems. Newton's laws of motion are the foundation of dynamics. They are simple in form, but they describe a wide range of natural behavior.

newton's first law: application

Newton's First Law and Friction

Newton's first law explains why friction changes an object's motion. It says that an object at rest stays at rest, and an object in motion keeps moving unless a net external force acts on it. A net external force is the overall force from outside the object that causes a change in velocity, meaning a change in speed or direction. This idea gives a cause-and-effect reason for motion, rather than just describing what we see. Galileo first developed the idea behind the first law of motion, and...

internal and external forces

External Forces and Motion Changes

External forces and motion changes are linked in Newton’s first law. A net external force causes a change in motion. External forces act on an object or system from outside that object or system. Internal forces come from inside the system of interest. They act on one part of an object and are exerted by another part of the same object. These forces do not cause acceleration when the whole system is studied. When analyzing motion, the internal forces are ignored. Instead, only the external...

newton's second law

Force, Mass, and Acceleration

Newton's second law connects net force, mass, and acceleration. It explains how an object's motion changes when external forces act on it. The law gives a clear cause-and-effect link that can be used to make calculations. All external forces on a system are added together to find the net force, or F net. A larger net external force produces a larger acceleration. The acceleration points in the same direction as the net force. Mass also affects the result. A larger mass means more inertia, so...

mass and weight

Weight Changes, Mass Stays Constant

Mass and weight are related, but they are not the same. In physics, weight is the pull of the Earth on an object. It depends on how far the object is from the center of the Earth. Mass is the amount of matter in an object, and it does not change with location. Everyday language can make this difference confusing. Medical records often list body weight in kilograms, even though the correct force unit is the newton. That can make mass and weight seem interchangeable. In physics, however, they...

weightlessness

Weightlessness in Free Fall

Weightlessness happens when contact forces disappear, even though gravity is still present. In physics, an object in free fall has only gravity acting on it. If the net external force on the object is its weight, the object is accelerating toward the center of the Earth. Galileo showed that, without air resistance, all objects fall with the same acceleration g. On Earth, falling objects are never truly in free fall because air always pushes upward with some resistance force. That is why real...

apparent weight

Scale Readings in Motion and Water

Scale readings can change when an object is moving or submerged in water. The force we call true weight is the gravitational force acting on an object. When motion or fluid forces are present, the reading can differ from that true weight. In water, this changed reading is called apparent weight, and it equals true weight minus the buoyant force. A bathroom scale in an elevator shows how this works. At rest, the scale reads the force the person pushes downward on it. The only forces on the...

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newton's third law: introduction

Newton's Third Law in Force Pairs

Newton's third law explains how force pairs work in motion and interactions. When one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction. A simple example is a person pushing on a wall. The wall pushes back on the person with an equal and opposite force. This is why Newton's third law is often described as action and reaction, where the action is the force exerted and the reaction is the force experienced afterward. <br...

newton's third law: examples

Newton's Third Law in Motion

Newton's third law explains how forces come in pairs during motion. It says that every action has an equal and opposite reaction. In these examples, the two forces act on different systems, so they do not cancel each other out. A swimmer pushing off the side of a pool shows this clearly. The swimmer pushes against the wall with their feet and then accelerates in the opposite direction. The wall pushes back with an equal and opposite force. If the swimmer is the system of interest, the wall's...

drawing free-body diagrams: rules

Free-Body Diagrams for Newton’s Laws

Free-body diagrams help students map the forces acting on an object in physics. They are used often when studying and applying Newton’s laws of motion. A clear diagram makes it easier to analyze a system before solving for motion. Start by drawing the object under consideration. If the object is treated like a particle, show it as a point and place that point at the origin of an x-y coordinate system. Then add every force that acts on the object as a vector. Do not include the net force on the...

free body diagrams: examples

Free Body Diagram Force Examples

Free body diagrams show the external forces acting on an object or system. The object is drawn as a single isolated point, or free body, so the forces are easier to analyze. Only forces that come from outside the object or system are included. These forces are shown as vectors pointing away from the free body. A person sitting on a chair is a simple example. The free-body diagram has two forces. The chair exerts an upward normal force, and gravity pulls downward with the weight. A rocket sled...

inertial frames of reference

Newton's First Law and Reference Frames

Newton's first law helps identify inertial reference frames. An inertial reference frame is one in which Newton's first law holds true. In that frame, an object with no net force moves at constant velocity. A key idea is that any frame moving at constant velocity relative to an inertial frame is also inertial. For that reason, inertial frames can be found by comparing motion from one frame to another. The laws of physics do not give one inertial frame special status over another. In nature, a...

non-inertial frames of reference

Why Motion Seems Different in Accelerating Frames

A non-inertial frame of reference is a frame that accelerates, decelerates, or rotates relative to an inertial frame. In these frames, motion can look unusual because the observer is moving with the system. That is why an airplane taking off, a car turning a corner, a merry-go-round, and a tropical cyclone can all be examples of non-inertial motion. These situations can show inertial forces, which seem to appear because the frame itself is accelerating or rotating. The force does not come from...

centrifugal force

Rotating Frames and Pseudo Forces

Pseudo forces, also called fictitious forces, appear in a rotating frame of reference when compared with an inertial frame. They are not real forces. Instead, they are mathematical tools that help make Newton&amp;#39;s laws of motion easier to use in a non-inertial frame. Common examples include centrifugal, Coriolis, and Euler forces. These forces matter in mechanics, astrophysics, and fluid dynamics. In these areas, motion is often described from a frame that is not inertial. That is why...

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key terms and concepts

Explore Newton's first law, inertia, and how external forces change motion. See how constant velocity, straight-line motion, and real-world examples fit together.

Newton's First Law and Inertia | JoVE K12

physics

JoVE Core Physique présente plusieurs branches de la physique fondamentale grâce à des vidéos animées concises et faciles à comprendre ; cela inclut: la cinématique, la dynamique, la mécanique des fluides, la mécanique statique, les ondes et l'acoustique. En parallèle, les vidéos de scientifiques à l'action démontrent l'application de concepts associés à ces domaines dans des expériences de recherche classiques et originales réalisées dans des laboratoires modernes du monde entier.

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Physical Science

Forces And Motion

Dynamics (how forces affect motion)

Forces, Momentum And Motion

newton-s-laws-applied-to-complex-problems

Newton's laws applied to complex problems

Tennessee Academic Standards

High School

Motion and Stability: Forces and Interactions

PHYS.PS2.4

Virginia  Standards of Learning

HIgh School

PS.8

PS.8.b

PH.3

PH.3.a

Arizona Science Standards

HS.P3

HS.P3U1.6

Alabama Course of Study Science

Earth and Space Science

Earth's Place in the Universe

9-12.ESS.1.2.a

9-12.ESS.1.3

9-12.P.1.2

Florida Department of Education

SC.912.P.12

SC.912.P.12.3

SC.912.P.12.8

Texas Essential Knowledge and Skills

PHYS.5

PHYS.5.E

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Forces and Interactions

HS-PS2-1.

Georgia Standards of Excellence

SPS8.

SP2.

Newton’s Laws of Motion

Position and Displacement

The position of an object defines its location relative to a convenient frame of reference at any particular time. A frame of reference is an arbitrary ...

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 ...

Instantaneous Velocity - I

The average velocity during a time interval cannot tell us how fast or in what direction a particle is moving at any given time during the interval. To ...

Instantaneous Velocity - II

Instantaneous velocity is the quantity that measures how fast an object is moving along its path. In other words, the instantaneous velocity of an object ...

Average Acceleration

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Instantaneous Acceleration

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Kinematic Equations - I

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Kinematic Equations - II

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Kinematic Equations - III

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Kinematic Equations: Problem Solving

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Free-falling Bodies: Introduction

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Free-falling Bodies: Example

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velocity-and-position-by-graphical-method

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 ...

Velocity and Position by Integral Method

If acceleration as a function of time is known, then velocity and position functions can be derived using integral calculus. For constant acceleration, ...

Use models (graphs, equations, diagrams) to infer motion in one dimension.

PS.Phy.1.1

Position and Displacement Vectors

To describe the motion of an object, one should first be able to describe its position (where it is at any particular time). More precisely, the position ...

average-and-instantaneous-velocity-vectors

Average and Instantaneous Velocity Vectors

To calculate other physical quantities in kinematics, the time variable must be introduced. The time variable not only allows us to state where an object ...

Acceleration Vectors

In everyday conversation, accelerating means speeding up. Acceleration is a vector in the same direction as the change in velocity, &#916;v, therefore the ...

Direction of Acceleration Vectors

Acceleration occurs when velocity changes in magnitude (an increase or decrease in speed), direction, or both. Although acceleration is in the direction ...

Projectile Motion

An object thrown in the air follows a parabolic path under the influence of Earth&#39;s gravitational force. The motion of such an object is called ...

/files/media/science-education/science-education-thumbs/12634.jpg

Projectile Motion: Equations

Projectile motion is commonly observed in our day-to-day life. For example, a basketball thrown by a player, an arrow shot from a bow, and kids jumping ...

Projectile Motion: Example

The theory of projectile motion is very useful for players of several sports to improve their performance. For example, a javelin thrower needs to throw ...

principle-linear-impulse-momentum-for-single-particle-problem

Principle of Linear Impulse and Momentum for a Single Particle: Problem Solving

Consider a massless pulley system consisting of a wooden box and a cylinder of known masses. Determine the speed of the attached objects at a specific ...

Non-uniform Circular Motion

In&#160;uniform circular motion, the particle executing circular motion has a constant speed, and the circle is at a fixed radius. However, not all ...

Relative Velocity in One Dimension

The understanding of the concept of reference frames is essential to discuss relative motion in one or more dimensions. When we say that an object has a ...

Relative Velocity in Two Dimensions

Relative velocity is the velocity of an object as observed from a particular reference frame, or the velocity of one reference frame with respect to ...

Use models (graphs, equations, diagrams) to infer motion in two dimensions.

PS.Phy.1.2

Force

Forces affect every moment of our life. Our bodies are held to the Earth by force, and they are held together by the forces of charged particles. When we ...

Types of Forces

In most situations, forces can be grouped into two categories: contact forces and field forces.&#160; Contact forces occur as a result of direct physical ...

Drawing Free-body Diagrams: Rules

The first step in describing and analyzing most phenomena in physics involves the careful drawing of a free-body diagram. Free-body diagrams are useful in ...

Free Body Diagrams: Examples

Solving problems that involve forces is easy using free-body diagrams. A free-body diagram is a sketch showing all the external forces that are acting on ...

Use free body models to qualitatively and quantitatively analyze systems of forces in one dimension and two dimensions.

PS.Phy.2.1

Motion draws our attention. Motion itself can be beautiful, causing us to marvel at the forces needed to create spectacular sights, such as that of a ...

Newton's First Law: Application

Experience suggests that an object at rest remains at rest if left alone, and that an object in motion tends to slow down and stop unless some effort is ...

Internal and External Forces

Newton&#39;s first law states that a net external force causes a change in motion. External forces act on an object or system, originating outside of the ...

Newton's Second Law

Newton&#39;s second law is closely related to his first law of motion. It mathematically gives the cause-and-effect relationship between force and changes ...

Mass and Weight

Mass and weight are often used interchangeably in everyday conversation. For example,&#160; medical records often show our weight in kilograms, but never ...

Carry out investigations to explain the interactions of forces on an object according to Newton's Laws of Motion.

Analyze the motion of objects using time, distance, displacement, speed, velocity, and acceleration.

Newton's First Law and Inertia

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