Name: scalar quantities in physics
Uploaded: 2023-09-22T11:49:38.000Z
Duration: 1 min 21 s
Channel: JoVE
Description: Scalar quantities in physics have size only. They do not include direction. This makes them different from vector quantities. Common scalar examples include mass, temperature, time, and energy. Each one can be described with a number and a unit. Because direction is not part of the value, scalars are often easier to compare and measure.

Physikalische Größen wie Zeit, Masse und Entfernung haben eine Größe, aber keine Richtung. Solche Größen werden als skalare Größen bezeichnet.
Sie werden als numerischer Wert ausgedrückt, gefolgt von einer physikalischen Einheit. Die Masse eines Apfels beträgt beispielsweise 100 g. 
Skalare unterscheiden sich von Vektoren, da Vektoren sowohl Größe als auch Richtung haben.
Zum Beispiel hängt die Masse eines Objekts von der Menge an Materie in einer Substanz ab und ist eine skalare Größe, während sein Gewicht, also die Kraft, die aufgrund der Erdanziehungskraft ausgeübt wird, eine Vektorgröße ist.
In ähnlicher Weise ist die Entfernung eine skalare Größe, während die Verschiebung, d. h. die Änderung der Position eines Objekts, eine Vektorgröße ist.
Skalare werden mit kursiven Buchstaben gekennzeichnet.
Skalare können negativ sein, wie z. B. die Ladung eines Elektrons oder der Messwert einer Thermometerskala.
Hier stellt das Minuszeichen den Punkt auf einer Skala oder die Art der Entität dar.
Bei Celsius- und Fahrenheit-Thermometern zeigen die Skalen an unterschiedlichen Punkten Null an. Daher wird die negative Temperatur auch bei unterschiedlichen Skalenwerten angezeigt.

einführung in scaler

Viele vertraute physikalische Größen können vollständig durch eine einzige Zahl und die entsprechende Einheit angegeben werden. Zum Beispiel "eine Unterrichtseinheit dauert 50 Minuten" oder "der Gasbehälter in meinem Auto fasst 65 Liter" oder "der Abstand zwischen den beiden Pfosten beträgt 100 Meter". Eine physikalische Größe, die auf diese Weise vollständig angegeben werden kann, wird als skalare Größe bezeichnet. Das Wort "skalar" ist ein Synonym für "Zahl". Zeit, Masse, Entfernung, Länge, Volumen, Temperatur und Energie sind einige Beispiele für skalare Größen.

Skalare Größen mit denselben physikalischen Einheiten können gemäß den üblichen Regeln der Algebra für Zahlen addiert oder subtrahiert werden. Zum Beispiel dauert eine Unterrichtseinheit, die 10 Minuten früher endet als 50 Minuten, 50 Minuten - 10 Minuten = 40 Minuten. Ebenso ergibt eine Portion Mais mit 60 Kalorien gefolgt von einer Portion Donuts mit 200 Kalorien 60 Kalorien + 200 Kalorien = 260 Kalorien an Energie. Wenn wir eine skalare Größe mit einer Zahl multiplizieren, erhalten wir dieselbe skalare Größe, jedoch mit einem größeren (oder kleineren) Wert. Zum Beispiel hatte das Frühstück von gestern 200 Kalorien an Energie und das heutige Frühstück hat viermal so viel Energie wie gestern, dann hat das heutige Frühstück 4 x 200 Kalorien = 800 Kalorien an Energie. Zwei skalare Größen können auch miteinander multipliziert oder dividiert werden, um eine abgeleitete skalare Größe zu bilden. Zum Beispiel, wenn ein Zug eine Strecke von 120 km in 1 Stunde zurücklegt, beträgt seine Geschwindigkeit 120.000 m / 3600 s = 33 m/s, wobei die Geschwindigkeit eine abgeleitete skalare Größe ist, die durch Teilen der Entfernung durch die Zeit erhalten wird.

Dieser Text ist angepasst von <a href="https://openstax.org/books/university-physics-volume-1/pages/2-1-scalars-and-vectors">Openstax, University Physics Volume 1, Abschnitt 2.1: Skalare und Vektoren.</a>

Einführung in Scaler

Viele bekannte physikalische Größen lassen sich durch die Angabe einer einzigen Zahl und der entsprechenden Einheit vollständig angeben. Zum Beispiel: "Eine Unterrichtsstunde dauert ...

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Introduction to Scalers

scalar quantities in physics

Scalar quantities in physics have size only. They do not include direction. This makes them different from vector quantities.

Common scalar examples include mass, temperature, time, and energy. Each one can be described with a number and a unit. Because direction is not part of the value, scalars are often easier to compare and measure.

Scalar Quantities in Physics

introduction to scalers

Scalar quantities in physics have size only. They do not include direction. This makes them different from vector quantities. Common scalar examples include mass, temperature, time, and energy. Each one can be described with a number and a unit. Because direction is not part of the value, scalars are often easier to compare and measure.

vector or cross product

Cross Product of Two Vectors

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introduction to vectors

Vectors in Motion and Direction

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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Measurement Units, Standards, and SI Basics

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accuracy and precision

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position and displacement

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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...

mass and weight

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acceleration due to gravity on earth

Free-Fall Acceleration on Earth

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key terms and concepts

Learn how scalar quantities are used in physics, with clear examples like mass, temperature, time, and energy for high school students.

Scalar Quantities in Physics | JoVE K12

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Scalar Quantities in Physics

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