A scalar magnitude It is a numerical quantity whose determination only requires the knowledge of its value with respect to a certain unit of measure of its same kind. Some examples of scalar quantities are distance, time, mass, energy, and electric charge..
Scalar quantities are generally represented by a letter or by the absolute value symbol, for example TO or ǀTOǀ. The magnitude of a vector is a scalar magnitude and can be obtained mathematically by algebraic methods..
Likewise, scalar quantities are represented graphically with a straight line of a certain length, without specific direction, related to a scale factor..
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In Physics, a scalar quantity is a physical quantity represented by a fixed numerical value and a standard unit of measurement, which does not depend on the reference system. Physical quantities are mathematical values related to measurable physical properties of a physical object or system..
For example, if you want to obtain the speed of a vehicle, in km / h, just divide the distance traveled by the time elapsed. Both quantities are numerical values accompanied by a unit, therefore speed is a scalar physical quantity. A scalar physical quantity is the numerical value of a measurable physical property without a specific orientation or sense..
Not all physical quantities are scalar quantities, some are expressed by means of a vector that has a numerical value, direction and sense. For example, if you want to obtain the speed of the vehicle, you must determine the movements made during the elapsed time.
These movements are characterized by having a numerical value, a direction and a specific sense. Consequently, the speed of the vehicle is a vector physical quantity as is the displacement.
-Described with a numeric value.
-Operations with scalar quantities are governed by basic algebraic methods such as addition, subtraction, multiplication, and division..
-The variation of a scalar quantity only depends on the change in its numerical value.
-It is represented graphically with a segment that have a specific value associated with a measurement scale.
-The scalar field allows determining the numerical value of a scalar physical quantity at each point in physical space.
The scalar product is the product of two vector quantities multiplied by the cosine of the angle θ that they form with each other. When the scalar product of two vectors is calculated, the result that is obtained is a scalar quantity.
The dot product of two vector quantities to Y b it is:
a.b = ǀaǀǀbǀ.cosθ = ab.cos θ
to= is the absolute value of the vector to
b= absolute value of the vector b
A scalar field is defined by associating a scalar magnitude at each point in space or region. In other words the scalar field is a function that shows a position for each scalar quantity within the space.
Some examples of scalar field are: the temperature at each point on the Earth's surface in an instant of time, the topographic map, the pressure field of a gas, the charge density and the electric potential. When the scalar field does not depend on time it is called stationary field
When representing graphically the set of points of the field that have the same scalar magnitude equipotential surfaces are formed. For example, the equipotential surfaces of point electric charges are concentric spherical surfaces centered in the charge. When an electric charge moves around the surface the electric potential is constant at every point on the surface.
Here are some examples of scalar quantities that are physical properties of nature.
It is the average kinetic energy of the particles in an object. It is measured with a thermometer and the values obtained in the measurement are scalar quantities associated with how hot or how cold an object is.
The length consists of the dimension of an object considering its extension in a straight line. The unit of measurement used in the International System of Units (SIU) is the meter and is denoted by the letter m.
One of the most common uses is that of time. It can be measured in seconds, minutes and hours. It is a magnitude that is used to measure the interval in which events occur.
For example, the duration of a soccer game is 90 minutes.
Pressure is a scalar physical quantity that measures force in a perpendicular direction per unit area. The unit of measurement used is the Pascal and is denoted by the syllable Pa or simply by the letter P.
An example is the ambient pressure, which is the weight that the mass of air in the atmosphere exerts on things..
Energy is defined as the ability of matter to act chemically or physically. The unit of measurement used is joules (joule) and is denoted by the letter J.
To obtain the mass of a body or object it is necessary to count how many particles, atoms, molecules it has, or to measure how much material the object integrates. A mass value can be obtained by weighing the object with a balance and it is not necessary to set the orientation of the body to measure its mass..
It is associated with the three-dimensional space that a body or substance occupies. It can be measured in liters, milliliters, cubic centimeters, cubic decimeters among other units and it is a scalar quantity.
The measurement of the speed of an object in kilometers per hour is a scalar quantity, it is only required to establish the numerical value of the object's path as a function of the elapsed time.
The protons and neutrons of subatomic particles have an electrical charge that is manifested by the electrical force of attraction and repulsion. Atoms in their neutral state have zero electric charge, that is, they have the same numerical value of protons as neutrons.
Energy is a measure that characterizes the ability of a body to perform work. By the first principle of Thermodynamics it is established that the energy in the universe remains constant, it is not created or destroyed, it is only transformed into other forms of energy.
The electric potential at any point in space is the electric potential energy per unit charge, it is represented by equipotential surfaces. The potential energy and the electric charge are scalar quantities, therefore the electric potential is a scalar quantity and depends on the value of the charge and the electric field..
It is the measure of the amount of mass of a body, particles or substances in a certain space and is expressed in units of mass per units of volume. The numerical value of the density is obtained, mathematically, dividing the mass by the volume.
Luminous intensity is the luminous flux in a certain direction, radiated by a solid angle unit. The unit of measurement is the candela, denoted by the form cd.
More commonly, the light intensity is what is called brightness. This is present in objects such as a light bulb, a telephone or any object that emits light.
The unit of measurement used to measure the amount of substance is the mole. This is a very important scalar quantity in the field of chemistry..
A mole contains Avogadro's number of particles, and its mass is its atomic or molecular mass expressed in grams.
Frequency is the number of times or repetitions of a periodic phenomenon or event, carried out in a given unit of time. The unit of measurement used for this scalar quantity is hertz or hertz and is denoted by the letters Hz.
For example, a young person may hear sounds that are between 20 Hz and 20,000 Hz. When the sound falls outside of that band, people cannot perceive it..
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