Name: newton's first law and reference frames
Uploaded: 2023-04-30T10:54:21.000Z
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Channel: JoVE

K12 Standards

Pennsylvania State Academic Standards

9-12

Physical Science

Forces and Interactions

3.2.9-12.J

Inertial Frames of Reference

O quadro de referência no qual as leis de Newton são válidas é chamado de sistema de referência inercial. O objeto relativo a este quadro de referência continua em repouso ou se move com uma velocidade constante.
Considere um carro em movimento. O passageiro está se movendo junto com o carro em relação à Terra. Quando o carro para repentinamente, o passageiro experimenta um empurrão para frente, apesar de nenhuma força resultante agir sobre ele.
Embora o passageiro se mova para frente em relação ao carro, sua velocidade em relação à Terra é mantida.
A inércia do passageiro tende a manter sua velocidade em relação à Terra devido à primeira lei do movimento de Newton. Aqui, o referencial ligado à Terra pode ser considerado como um referencial inercial.
Embora a velocidade da Terra não seja constante devido à sua rotação e revolução, ela pode ser aproximada como um referencial inercial, pois seus efeitos são insignificantes no movimento dos objetos na superfície da Terra.

Não há conflitos de interesse declarados.

referenciais inerciais

A primeira lei de Newton é geralmente considerada como uma afirmação a respeito de referenciais. Ela fornece um método para identificar um tipo especial de referencial: o referencial inercial. Em princípio, podemos fazer a força resultante em um corpo ser igual a zero. Se sua velocidade em relação a um determinado referencial for constante, então esse referencial é considerado como sendo inercial. Portanto, por definição, um referencial inercial é um referencial no qual a primeira lei de Newton é válida. A primeira lei de Newton se aplica a objetos com velocidade constante. A partir desse fato, podemos inferir o seguinte:

Um referencial que se move com velocidade constante em relação a um referencial inercial também é inercial.

Referenciais inerciais são comuns na natureza? Descobriu-se que, dentro uma margem de erro experimental, um referencial em repouso em relação às estrelas mais distantes, ou "fixas", é inercial. Todos os referenciais que se movem uniformemente em relação a esse referencial das estrelas fixas também são inerciais. Por exemplo, um referencial não rotativo ligado ao Sol é, para todos os propósitos práticos, inercial, porque sua velocidade em relação às estrelas fixas não varia em mais de uma parte em 1010. A Terra sofre aceleração em relação às estrelas fixas porque ela gira em seu eixo e orbita ao redor do Sol; portanto, um referencial ligado à sua superfície não é inercial. No entanto, para a maioria dos problemas, esse referencial serve como uma aproximação suficientemente precisa de um referencial inercial, pois a aceleração de um ponto na superfície da Terra em relação às estrelas fixas é relativamente pequena (<3,4 x 10-2 m/s2). Assim, consideramos os quadros de referência fixos na Terra como inerciais, a menos que indicado de outra forma. Por fim, nenhum referencial inercial é mais especial do que outro. No que diz respeito às leis da natureza, todos os referenciais inerciais são equivalentes. Ao analisar um problema, escolhemos um referencial inercial em vez de outro simplesmente com base na conveniência.

Este texto foi adaptado de <a href="https://openstax.org/books/university-physics-volume-1/pages/5-2-newtons-first-law">Openstax, University Physics Volume 1, Section 5.2: Newton's First Law.</a>

Referenciais inerciais

A primeira lei de Newton é geralmente considerada uma afirmação sobre sistemas de referência. Ele fornece um método para identificar um tipo especial de referência ...

Education

JoVE Core

Physics

Física

Unit 1

Unidade 1

Newton's Laws of Motion

Leis do Movimento de Newton

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

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 frame at rest relative to the most distant fixed stars is inertial within experimental error. Any frame moving uniformly with respect to that fixed-star frame is also inertial. A non-rotating frame attached to the Sun is, for practical purposes, inertial because its velocity relative to the fixed stars changes by less than one part in 10^10.

A frame attached to Earth's surface is not truly inertial because Earth rotates on its axis and revolves around the Sun. Even so, the acceleration of a point on Earth's surface relative to the fixed stars is small, less than 3.4 x 10^-2 m/s^2. That is why Earth-fixed frames are usually treated as inertial unless stated otherwise.

Newton's First Law and Reference Frames

force

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newton's first law: introduction

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newton's first law: application

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newton's second law

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newton's third law: introduction

Newton's Third Law in Force Pairs

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inertial frames of reference

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non-inertial frames of reference

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centrifugal force

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key terms and concepts

Learn how Newton's first law identifies inertial reference frames, why Earth is only an approximation, and why all inertial frames are equivalent.

Newton's First Law and Reference Frames | JoVE K12

physics

JoVE Core - Fisica apresenta a teoria e a aplicação de tópicos fundamentais da física, incluindo cinemática, dinâmica, mecânica dos fluidos, estática, ondas e acústica, com vídeos animados concisos e de fácil compreensão. Além disso, os vídeos de cientistas em ação demonstram a aplicação de conceitos relacionados em experimentos de pesquisa clássica e original realizados nos laboratórios de todo o mundo hoje em dia.

Louisiana Student Standards for Science

High School

motion-and-stability-forces-and-interactions

Motion And Stability: Forces And Interactions

HS-PS2-2

HS-PS2-3

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Forces And Motion

Motion

Tennessee Academic Standards

Motion and Stability: Forces and Interactions

PHYS.PS2.14

Virginia  Standards of Learning

HIgh School

PS.8

PS.8.b

PH.3

PH.3.a

Next Generation Science Standards

Florida Department of Education

SC.912.P.12

SC.912.P.12.3

SC.912.P.12.8

SC.912.P.12.9

Texas Essential Knowledge and Skills

PHYS.5

PHYS.5.C

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Forces and Interactions

HS-PS2-1.

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3.2.9-12.I

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3.2.9-12.M

Newton's First Law and Reference Frames

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