Name: tracking motion with position and displacement
Uploaded: 2023-09-22T11:49:39.000Z
Duration: 1 min 31 s
Channel: JoVE

Чтобы описать движение объекта, необходимо указать его положение относительно удобной системы отсчета. Произвольный набор осей, описывающий положение и движение объекта, называется системой отсчета.
Как правило, в качестве системы отсчета используются Земля или стационарные объекты на Земле. Например, положение самолета во время его взлета может быть описано относительно Земли в целом или диспетчерской вышки аэропорта. Чтобы описать положение объекта в одномерном движении, мы часто используем переменную x.
Теперь предположим, что объект движется относительно системы отсчета — например, автомобиль движется влево относительно здания, а затем положение автомобиля меняется. Такое изменение положения называется смещением.
Однако числовое значение x вдоль прямой линии определяет положение объекта, в котором он может находиться. Любое изменение положения вдоль этой линии обозначается смещением, где Δx — смещение и вычисляется путем вычитания начального положения из конечного положения. Это векторная величина, так как она указывает направление, и, в зависимости от выбора положительного направления, может быть как положительной, так и отрицательной.

Положение и смещение

Положение объекта определяет его местоположение относительно удобной системы отсчёта в конкретный момент времени. Система отсчёта — это произвольный набор осей, с помощью которых описывается положение и движение объекта. Земля часто используется в качестве системы отсчёта, и мы часто описываем положение объекта относительно неподвижных объектов на Земле. Например, запуск ракеты можно описать с точки зрения положения ракеты относительно Земли в целом. С другой стороны, положение велосипедиста можно описать относительно зданий, которые он проезжает. В других случаях мы используем системы отсчёта, которые не являются неподвижными, но движутся относительно Земли. Для описания положения человека в самолёте мы, например, используем самолёт, а не Землю, в качестве системы отсчёта. Для описания положения объекта, движущегося в одном измерении, мы часто используем переменную x.

Если объект перемещается относительно системы отсчёта, то положение объекта изменяется. Например, если преподаватель движется вправо относительно доски, то его положение изменяется. Это изменение положения называется перемещением. Слово "перемещение" подразумевает, что объект перемещался или смещался. Хотя положение представляет собой числовое значение x на прямой линии, где может находиться объект, перемещение даёт изменение положения вдоль этой линии. Поскольку перемещение указывает направление, оно является векторной величиной и может быть как положительным, так и отрицательным в зависимости от выбранного направления как положительного.

Кроме того, анализ движения может содержать множество вложенных перемещений. Например, если справа положительное направление, и объект движется 2 метра вправо, а затем 4 метра влево, индивидуальные перемещения составляют 2 метра и 4 метра соответственно. Перемещение обозначается как Δx, что является изменением положения. Мы всегда находим перемещение, вычитая начальное положение из конечного положения.

Этот текст адаптирован из <a href="https://openstax.org/books/university-physics-volume-1/pages/3-1-position-displacement-and-average-velocity">Openstax, University Physics Volume 1, Section 3.1: Position, Displacement, and Average Velocity.</a>

Положение объекта определяет его местоположение относительно удобной системы отсчета в любой конкретный момент времени. Система отсчета – это произвольная ...

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Mechanical Engineering

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Unit 1

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Physics Basics

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KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

Position and Displacement

tracking motion with position and displacement

Position and displacement are key ideas in straight-line motion. Position tells where an object is located compared with a chosen starting point, called the origin. Displacement describes how far and in what direction the object has moved from its starting position.

These ideas help describe motion clearly. Position can change as an object moves. Displacement focuses on the change in position, not just the path taken. That makes it useful for comparing motion in a simple and precise way.

Tracking Motion with Position and Displacement

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Tracking Motion with Position and Displacement

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