Name: using vectors to describe motion
Uploaded: 2023-09-22T11:49:39.000Z
Duration: 1 min
Channel: JoVE

Considera una mosca in movimento. Per localizzare la sua posizione in uno spazio tridimensionale, viene utilizzato un sistema di coordinate cartesiane e i vettori unitari lungo l'asse forniscono la sua direzione.
La freccia vettoriale che si estende dall'origine alla posizione dell'oggetto è il vettore di posizione. Può essere rappresentato in termini di vettori unitari.
Il vettore di posizione è la somma delle componenti vettoriali su ciascun asse e le loro grandezze forniscono la posizione lungo ciascun asse.
Se la mosca continua il suo movimento, il suo vettore di posizione cambia e la differenza vettoriale tra i vettori di posizione è chiamata vettore di spostamento, Δr, che rappresenta il cambiamento di posizione.
Ad esempio, se la mosca si trova nel punto A e dopo il tempo t raggiunge il punto B, utilizzando i vettori di posizione di A e B, è possibile ottenere il vettore di spostamento della mosca per il tempo t.

vettori di posizione e spostamento

Per descrivere il moto di un oggetto, occorre prima saperne descrivere la posizione (dov'è in un determinato tempo). Più precisamente, la posizione ha bisogno di essere specificata relativamente ad un comodo quadro di riferimento. Un quadro di riferimento è un insieme arbitrario di assi dal quale la posizione e il moto di un oggetto sono descritti. La Terra viene spesso usata come sistema di riferimento per descrivere la posizione di un oggetto in relazione ad un oggetto stazionario sulla Terra.

Inoltre, diversi importanti tipi di moto avvengono solo in due dimensioni, cioè in un piano. Questi moti possono essere descritti con due componenti di posizione: velocità, e accelerazione. Se un oggetto si muove relativamente a un sistema di riferimento, allora la posizione dell'oggetto cambia. Questo cambio di posizione è chiamato spostamento. La parola spostamento implica che un oggetto si è mosso o è stato spostato. Visto che lo spostamento indica la direzione, è un vettore e può essere positivo o negativo, a seconda della scelta di direzione. Inoltre, un'analisi del movimento può avere molti spostamenti incorporati in esso e molte applicazioni di fisica possono avere una serie di spostamenti. Pertanto, lo spostamento è la somma degli spostamenti individuali, i quali dovrebbero essere valutati attentamente usando l'aggiunta di vettori.

Questo testo è adattato da <a href="https://openstax.org/books/university-physics-volume-1/pages/4-1-displacement-and-velocity-vectors">Openstax, University Physics Volume 1, Section 4:1 Displacement and Velocity Vectors.</a>

Vettori di posizione e spostamento

Per descrivere il movimento di un oggetto, si dovrebbe prima essere in grado di descrivere la sua posizione (dove si trova in un determinato momento). Più precisamente, la posizione ...

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Position and Displacement Vectors

using vectors to describe motion

Position and displacement vectors describe motion in physics. A position vector shows where an object is located relative to a chosen origin. A displacement vector shows how far and in what direction the object moves from one point to another.

These vectors are useful because they give a clear way to track movement in space. The video connects position and displacement to the idea of a reference point and shows how direction matters as much as distance. That makes them important for describing motion in one, two, or three dimensions.

The lesson also shows how to represent these vectors using arrows and coordinate systems. By comparing the starting point and ending point, students can see the difference between an object’s location and its change in position. This helps build the foundation for later topics in kinematics.

Using Vectors to Describe Motion

introduction to scalers

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vector or cross product

Cross Product of Two Vectors

The cross product of two vectors gives a new vector that is related to both original vectors. It is also called the vector product. In many physics problems, this operation helps describe quantities that depend on direction as well as size. The result of a cross product has a direction set by the two input vectors. It is not the same as ordinary multiplication. The transcript focuses on the vector or cross product as a core vector operation students use when working with vectors in science.

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Vectors describe quantities that have both size and direction. They are used in physics to show how motion, force, and other quantities act in space. A vector can be represented with an arrow. The length of the arrow shows the size, and the arrowhead shows the direction. This makes vectors useful for comparing how one quantity points relative to another. Scalars are different because they have size only and no direction. Understanding the difference between vectors and scalars is an important...

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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.

position and displacement vectors

Position and displacement vectors describe motion in physics. A position vector shows where an object is located relative to a chosen origin. A displacement vector shows how far and in what direction the object moves from one point to another. These vectors are useful because they give a clear way to track movement in space. The video connects position and displacement to the idea of a reference point and shows how direction matters as much as distance. That makes them important for describing...

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Free-Fall Acceleration on Earth

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Gravity is a force that pulls objects toward one another. On Earth, this force gives objects weight and keeps people, water, and other materials from drifting away. It also helps explain why planets and moons stay in motion around larger bodies. The strength of gravitational force depends on the masses of the objects involved. Larger masses create a stronger pull, while smaller masses create a weaker one. The distance between objects also matters, because gravity becomes weaker as objects move...

key terms and concepts

Learn how position vectors and displacement vectors describe an object’s location and movement in 1D, 2D, and 3D using arrows and coordinates.

Using Vectors to Describe Motion | JoVE K12

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Using Vectors to Describe Motion

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