What is the magnitude?
Of course, each of us, at the level of the most general idea, perfectly understands what a quantity is. Value is the length, volume, mass, or some other quantitative characteristic of an object or phenomenon. What does the value mean? If we hear that hailstorm was the size of a walnut, it means that the volume of one hail was approximately equal to the volume of walnut.
But if we are asked what is a scalar quantity, a random variable, a relative quantity, can we answer this question just as easily?
Let's try to figure everything out in order.
What is a physical quantity?
A physical quantity is a property of an object, phenomenon, or process that can be characterized quantitatively. For example, water poured into a decanter will have a certain volume, mass, density, and so on.
A physical quantity always has a numerical value indicating the units in which it was measured. For example, two containers arrived at the railway station. The mass of one of them is 1.5 tons, and the mass of the other is 1,500 kg.Which one is harder? As you may have guessed, in fact, the mass of both containers is the same. Just with the change of units, the numerical value of the mass has changed.
A random variable is a term for the mathematical theory of probability. A random variable takes a specific value in the course of any experience. But this value cannot be accurately known in advance. Examples of random variables:
- number of hits from 5 shots;
- the number of points on the top face of the dice, which will fall out after throwing it up;
- air temperature for tomorrow.
Scalar and vector values
A scalar value is a value that has only a numeric value. Approximate scalar values - time, mass, temperature, etc.
However, some physical quantities (speed, force, acceleration), besides the numerical characteristic, also have a direction. Such quantities are called vector. Vector magnitude, for example, the same speed, can also be measured. But the numerical value (modulus) of a vector quantity will not fully describe it, but only partially. To characterize a vector quantity completely, one must indicate the direction of its action in space.
Nominal and real values
The concepts of "nominal" and "real" value are used in the economy. The nominal value is an economic indicator expressed in monetary units. For example, your nominal salary is how much rubles you earned over the past month. And the real salary is how much goods and services you can really get for your nominal salary. If there is high inflation in the country, then the nominal wage can grow, and the real one can fall.
Constant and variable values
A constant value is a value that in a given system has only one specific and unchangeable value. An example is body mass. The value of a variable can vary depending on various factors. For example, the speed of the same car on the same track may vary depending on the desire of the driver.
Absolute and relative values
Absolute and relative values are operated by statistics. The absolute value is expressed in specific units of something. For example, per capita consumption of goods and services is expressed in rubles or dollars. Relative value is an indicator of comparison of absolute values.For example, you can determine the level of consumption of Russians today compared with the same period last year. You can see how, according to this indicator, Russians look relatively to citizens of India or Norway.
The average value is a statistical indicator that characterizes the typical value of a characteristic for a homogeneous group. Although all employees of the same enterprise receive different wages, it is possible to calculate the average wage at a given enterprise.
The average is sometimes more important than the specific. If you received 11,000 rubles for 11 months and earned 80,000 rubles in December, this does not mean that you came close to earning 80,000 rubles a month. Your average salary per year is 25,000 per month.
However, the average value may be misleading. If you ate 2 patties, and I ate one, then on average we ate one patty. But for me it does not matter. After all, you have become well fed, and I remained hungry.
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