A watt is a physical quantity that everyone has to deal with on a daily basis without even knowing it. What is measured by it, when did it arise, and by what formula can it be found? Let's find answers to all these questions.

What is a watt

First of all, it is worth knowing the definition of this term. So, watt is the unit used in the International SI system.

It can be of three types:

• Mechanical.
• Electric.
• Thermal.

History of appearance

For the first time, watts began to be used as a value for measuring power in Great Britain in 1882. Before that, horsepower was in use, and their understanding was different in individual countries.

The inventor of this unit of measure (watt) was the "father" of the industrial revolution - James Watt (there is a spelling of Watt). In honor of him, by the way, she was named. For this reason, like the joule (named after the surname of the British scientist James Prescott Joule), and the watt, in abbreviated form it is always written with a capital letter - W (in English W).

Since 1960, the watt has been a unit of power used throughout the world. After all, it was then that he was recognized

Power Formula

Having dealt with the definition and history of the appearance of a watt, it is worth knowing its formula. It looks like this: N = A / t. And it stands for work divided by time.

Sometimes, in order to find out the number of watts, a slightly different power formula is used: N \u003d F x V. In this example, the desired value is calculated not using work and time, but using force and speed data.

In fact, the second formula is a kind of adaptation of the classical one. It is simply taken into account that the work is equal to the derivative of the force by the distance (A \u003d F x S), and the speed is the quotient of the distance divided by the time (V \u003d S / t). If you put all these data: you get the following example: N = F x S / t = F x V.

Watts, volts and amps

In addition to the formula considered in the previous paragraph for finding the physical quantity under study, there is another one. It demonstrates the relationship between power (watts) and current (amps).

However, before getting acquainted with it, it is worth knowing a little more about these units of measurement.

Volt (V, in English V) is a unit of measure for electrical voltage. In formulas, it is denoted by the Latin letter U.

Ampere (A, in English also A) - a value characterizing the strength of an electric current, denoted by the letter I.

Relationship formula between power, voltage and current

Briefly considering the features of all these quantities, we obtain this formula.

It looks like this: P \u003d U x I. In it, P is power (watts), U is voltage (volts), I is current (amps).

If necessary, this formula can be modeled if the power is already known, but you need to find the current (I = P / U) or voltage (U = P / I).

With the modern development of technology, in order to find out how many watts are contained in a certain number of amperes, you can simply find a specialized power calculation program on the Internet and enter the available data into it. It is not difficult to do this, in the line of any search engine you need to look for the phrase “watt to ampere conversion calculator”, and the system will give the addresses of the desired sites.

Sub-multiple units W

In addition to practical applications, the units in question are often used to make numerous theoretical calculations. However, if the power is extremely small, writing watts using decimals with many zeros is rather impractical. To facilitate this task, scientists introduced submultiple units of W. They are usually written as powers with a minus.

To date, a dozen of them have been identified, but in practice, many of them are not used.

For example, the first two submultiple units of a watt: dW (deciwatt, equal to 10 -1 W) and cW (centiwatt, equal to 10 -2 W) are not recommended for use. But milliwatts (mW equals 10 -3), microwatts (µW equals 10 -6) and nanowatts (nW equals 10 -9 W) are among the most used. And not only in calculations, but also in the manufacture of various measuring instruments.

For example, in medical devices such as an electrocardiograph and an electroencephalograph, the units of measurement are microwatts (µW).

In addition to those listed above, there are five more submultiple units: picowatt (10 -12), femtowatt (10 -15), attowatt (10 -18), zeptowatt (10 -21) and ioktowatt (10 -24). However, all of them are used in rare cases, and then only in theoretical calculations.

Multiples of W

By itself, the unit in question is relatively small. For example, to wash one kilogram of laundry in one hour in an A ++ class automatic washing machine, you will need electricity. However, if we take into account that on average about 3.5 kilograms of things are washed at the same time, then 525 watts are consumed. And this is just one wash, but how many of them happen in a month or a year? A lot, as well as the number of watts consumed. To facilitate their recording, ten multiple units are allocated based on W, written as degrees.

As in the case of submultiples, the first two of them (decawatt - 10 1 and hectowatt - 10 2) are not commonly used, so they exist only "de jure".

It is worth noting that when writing abbreviations of multiple units, the first letters are often capitalized. This is done in order not to confuse megawatts (MW - 10 6) with microwatts (mW) and other similar values.

The most commonly used is the well-known to all - kilowatt (kW). It is equal to a thousand watts (10 3). The second most popular is the aforementioned megawatt. This unit is most often used in the electric power industry. Less commonly, it uses such quantities as gigawatts (GW - 10 9) and terawatts (TW - 10 12). For example, in one year, on average, humanity consumes about 1.9 TW of electricity.

The remaining four quantities - petawatts (PVt - 10 15), exawatts (EWt - 10 18), zettawatts (ZWt - 10 21) and iottawatts (IVt 10 24) - are very rarely used, mainly when carrying out theoretical calculations. For example, according to one of them, it is assumed that the total power of the energy radiated by the Sun is 382.8 IW.

Despite the many multiples and submultiples of a watt, it is not difficult to perform mathematical operations with them. The easiest way is to convert everything to watts and then perform actions with degrees.

Another easy way to find out watts (the amount when using large or small quantities associated with them) is to find an online calculator on the Internet. By the way, with its help you can even convert watts into horsepower.

Watts and watt hours

Having figured out what the unit of measurement is watt (as well as knowing its multiples and submultiples and the formulas for finding it), it is worth taking the time to consider such a close concept as watt-hours (Wh). Although the names for W and Wh are very similar, they represent slightly different concepts.

The second unit is used to measure the energy produced in a certain time period (one hour).

To make the difference more clear, it is worth considering the operation of an ordinary electric kettle with a power of 2200 watts. To prepare compotes for the winter, the hostess almost continuously heated water with it for one hour. During this time, the device used 2200 Wh. If a woman took a weaker 1100 W kettle, it would boil the same amount of liquid in two hours and still use the same 2200 Wh.

All electricity supplied to consumers is measured not in watts, but in watt-hours (more often in kilowatt-hours, also a ratio of one to a thousand). To confirm this, you can simply go to any house meter. Regardless of the country and manufacturer, next to the numbers (demonstrating the amount of electricity used) there will be a note “kilowatt-hour” (kWh). It can also be in English: kilowatt-hour (kW⋅h).

At the same time, the power of any power plant synthesizing it is measured in ordinary watts (kilowatts and megawatts).

Many of you have seen the difference in prices in domestic and Chinese online stores for high-power LEDs. A 50W model in China costs 100 rubles, in Russia 500 rubles. Outwardly, they are similar, power consumption is the same, no differences are visible.

In fact, there are many technical characteristics that the Chinese use to make LED as cheap as possible. At the same time, both quality and parameters suffer greatly. But for a bad and cheap diode, they don’t write real parameters, they indicate from high-quality LEDs. Usually they write the same standard 50.000 hours. service, the same power. Only 100W, 50W, 30W, 20W, 10W super bright white light LEDs will be considered. Infrared IR, UV UV, RGB will participate in separate reviews and tests.

• 1. Size
• 2. Parameters of Superbright LEDs
• 3. Characteristics from the Chinese
• 4. Specification example from Bridgelux
• 5. Price
• 6. Scatter of parameters
• 7. Base material
• 8. Conductors
• 9. The most powerful
• 10. Lenses for optics

Size

Sometimes the seller in the specifications for LEDs 10 W, 20 W, 30 W, 50 W, 100 W writes the size of the crystals used, in units of "mil". This is a unit of measurement equal to one thousandth of an inch, or 0.0254 millimeters. To check the seller for honesty, you can measure the size of the crystals with a micrometer. Only a complete disassembly is required with the dismantling of the silicone coating, the removal of the phosphor layer.

LED matrices consist of standard 1 watt crystals, which are placed with single-wool in the Emitter package. Standard chip dimensions are 30*30mil and 45*45mil, in millimeters 0.762*0.762mm and 1.143*1.143mm. Rated current 300mA.

The exception is the 10W LED, it has 9 of them. Another one was added by marketers to increase sales.

Parameters of Superbright LEDs

To reduce the cost, the Chinese decided to put smaller and worse crystals on 10W, 20W, 30W, 50W, 100W at 0.5W and 0.75W, for which the rated current is 150mA and 220mA. For them, 300mA will be too much, they will degrade and heat up a lot. Good crystals should be between 30*30mil and 45*45mil.

Correspondence of sizes and power:

1. 1W=45*45mil;
2. 1W=30*30mil;
3. 0.75W=24*40mil;
4. 0.5W=24*24mil.
5. 0.5W=20*20mil for SMD5730

Bridgelux, Epistar, Epileds

Characteristics from the Chinese

A caring seller places a table with the parameters of LED matrices on the product page. If these data are not indicated, then I do not advise buying in this place, there may be a large variation in quality.

In the table for 24*24mil, you can see that the seller indicates the standard power of 10W, 20W, 30W, 50W, 70W, 100W and the number of installed crystals. Pay close attention to voltage and current. For 100W, the number of volts is 30-32V, Ampere 2-2.1A.

We calculate the power for24*24mil:

• minimum 30V*2A = 60W;
• maximum 32V * 2.1A = 67.2W;
• that is, instead of the promised 100W, it will be 60-65W.

The value of 60-65W is still too high, since 1 chip per 0.5W, then it’s really 50W there, but they sold it to us as 100W. Crystals are already the cheapest and worst, so any overclocking is contraindicated for them.

Calculate for24*44mil:

• minimum 30V * 2.850A = 85.5W;
• maximum 32V * 3A = 96W;
• the average will be 90W.

According to the table, we got 90W, in reality there is 75W, they overestimated it by 15W.

Let's count for 30*30mil:

• minimum 32V * 2.8A = 89.6W
• maximum 34V * 3.5A = 119W
• average 105W

The 30*30mil size provides the promised specifications. The same chips are placed in ordinary high-quality single-wool 1W with a power consumption of 10W, 20W, 30W, 50W, 70W, 100W

Specification example from Bridgelux

I will show the characteristics of powerful LED COB matrices from world manufacturers. Use this table to compare with budget ones. The luminous flux depends on the color temperature, the higher it is, the better the Lumens per Watt efficiency. It also depends on the color rendering index, with CRI70 the light output index is up to 128 lm / watt.

The difference in these parameters for the same power, for example 50W, is:

• CRI90, 2700K, 50W = 80lm/W;
• CRI70, 5600K, 50W = 128lm/W;
• 128lm/w - 80lm/w = 48lm/w difference, or 60%.

Price

The most interesting thing remains, this is the price of such products for 10W, 20W, 30W, 50W, 100W. I will indicate the prices in rubles for which I bought. As you can see the price differs by 3-4 times. When buying cheap junk, do not hope for a miracle that you will be lucky and get a good one. the only way to long-term operation is to use an underestimated current. In this way, active degradation and excessive heating can be avoided.

Such chips can be heated to a maximum of 60 ° and this is the temperature of the crystal, not the case. The critical will be 70°. For powerful branded ones, heating is allowed up to 110 °, for the highest quality and most expensive ones up to 150 °.

The luminous flux, of course, they are decently overpriced, the Chinese promises 100 lm / watt. Really happens from 60 to 80lm/w. For a quality branded one, this indicator is 105-120 lm / watt.

This information can be used to return money for the goods. You were deceived if the real power is 2 times less. We open a dispute on Aliexpress and ask for a refund of half the amount. Two weeks ago I bought such diodes for 2000 rubles. Soon they will come and I will ask for damages for deceit.

Scatter of parameters

Cheap LED chips for 10, 20, 50, 100 watts can have quite large differences in parameters. Because of this, some of the chips will heat up and degrade more, respectively, they will fail faster. To check, turn on at a very low current so that they glow a little. Visually, you will see that some crystals shine strongly, while others do not.

Base material

To reduce the cost, the Chinese use aluminum or its alloys as the base material. For quality, copper is used, which has better thermal conductivity. Therefore, a high-quality powerful LED should weigh 2-3 more than a cheap one.

conductors

To connect the crystals to the contacts, thin threads are used in an amount of 2 to 4 pieces. And here you can save money by replacing 4 gold threads with copper ones or reducing the number to 2 pieces. Another option is a copper thread covered with gold on top, it is very difficult to find the difference.

They are responsible for the current strength at which the diode can operate. They are made with a margin to withstand power surges and not burn out. There are fewer of them on budget matrices or they are made of copper.

Some of you have already experienced a similar phenomenon with LED position lamps. A Chinese light bulb with a power stabilizer will work less hours than a lamp on branded diodes without a stabilizer. The branded one has high-quality conductors that can withstand surges in the car network, which can be up to 30V.

The most powerful

In addition to the common ones for 10 watts, 20 watts, 30 watts, 50 watts, 100 watts, there are also the most powerful LEDs for 150W, 300W, 500W. According to the results of testing, the luminous flux in the presence of optics on a 500-watt diode melts snow at a distance of several meters. Due to the large size of the installed crystals, very fat and heated photons fly out of them.

Lenses for optics

When manufacturing LED spotlights and fixtures, the most difficult thing is to find the right housing that will focus, protect, cool. Usually a radiator and a driver are available as the basis of the design. One of the easiest ways to cover a powerful LED and focus its light output is to install a collimator lens. The kit consists of a chrome frame, reflector and lens. Light focusing can be from 5° to 90°. It is enough to fix the LED on any radiator and close it from above. It will be completely protected from external influences, suddenly the crows will peck it out.

An important parameter characterizing the performance of any devices and devices is power. The greater this characteristic, the greater the performance of the mechanisms. However, the higher the value, the higher the resource consumption. Therefore, this value is one of the important characteristics for electrical appliances and is often indicated on the packaging, the device itself or in the attached instructions.

Attention! The higher the value, the higher the power consumption of the device. Therefore, before choosing a device, you need to decide on the amount of work that you plan to perform with it. You need to know this in order not to overpay extra money when buying.

Power

According to Wikipedia, this is a value that characterizes the rate of change in the energy of the system, as well as its transfer and transformation. In physics, it is calculated as the work done by the device in a unit period of time.

Depending on the section of physics, it is indicated by the following symbols:

• Designation in mechanics - N, P;
• The designation in electrodynamics is R. According to the wiki, this symbol is taken from the Latin word potestas, which means power in translation.

You can also find the designation with the symbol W, taken from the English word watt.

Thus, the following formula is used for the calculation:

N = A/Δt, where:

• A - the work that the mechanism performs, measured in joules (J);
• Dt is a period of time, measured in seconds (s).

Also, to measure a physical quantity, formulas in mechanics are used:

P = F × v × cos α, where:

• F - strength,
• v - speed,
• α is the angle between the vectors F and v.

The instantaneous value is defined as the product of the instantaneous force (F) to the instantaneous speed (u), that is:

For a DC circuit, the formula will be as follows:

P = I × U, where:

• I - current strength,
• U is the voltage in the circuit.

Watt

The unit of power in physics is Watt (watt, W).

Initially, calculations were made in horsepower (hp). This unit was introduced by the Scottish scientist and inventor James Watt. She showed the number of horses that was required to do the work that the steam engine created by this inventor did. In Europe, they use mainly metric horsepower. It was defined as a value equal to the power expended for the uniform lifting of a body weighing 75 kg at a speed of 1 m/s.

Watt was officially recognized in 1882 at the Second Congress of the British Scientific Association. Named after J. Watt.

In the middle of the 20th century, the 19th General Conference on Weights and Measures introduced the unit of power, watt, into the International SI system. Based on the formula for calculation, wattis a derived unit of measure, which is entered as:

Also, in watts, such physical quantities as heat flux, radiation flux, sound energy flux, energy flux of ionizing radiation, etc. are measured.

On the other hand, 1 watt can be defined as:

• 1 W = 1N m/s;
• 1 W = 1V 1A.

In addition, the following units are also used (or were used previously):

• Horsepower;
• calorie per second;
• kilogram meter/second;
• erg per second.

Table for conversion between off-system units and watt

Attention!Currently, horsepower is used mainly to measure the power of car engines. At the same time, the calculations take into account that 1 hp. » 0.735 kilowatts.

In addition to metric horsepower, electrical, hydraulic, and mechanical horsepower are used in physics:

• mechanical HP » 0.745 kilowatts;
• electric hp » 0.746 kilowatts.

For your information. To convert values ​​from non-system units to system units (Watt), there are a large number of converters on the Internet that allow you to quickly convert data online from one unit of measure to another.

To record large or, conversely, small values ​​​​of quantities, the use of special standard prefixes is allowed. For example, a thousand watts equals one kilowatt.

Prefixes were first introduced by the General Conference on Weights and Measures in 1960.

Translation table for frequently used prefixes

What is a wattmeter

In order for the equipment not to deteriorate during operation, and there is no short circuit in the network, it is necessary to check that the power of the devices does not exceed the total value of the network.

For a DC circuit, it can be determined by knowing the values ​​​​of current and voltage. To measure these parameters of the electrical network, an ammeter and a voltmeter are used. An ammeter measures the current (in amperes), and a voltmeter measures the voltage (in volts) applied to the network. Further, these two parameters are multiplied and the desired value is obtained in watt.

To measure in AC networks, special devices are used, which are called wattmeters.

Depending on the purpose, there are several types of wattmeters:

• Power meter - used to find the number of watts in the optical or radio range;
• Kilowattmeter - used when measuring large values ​​(of the order of hundreds of kilowatts);
• Milliwattmeter - for measuring small values ​​\u200b\u200b(less than one);
• Varmeter - serves to measure the indications of the reactive power of the circuit;
• Wattvarmeter - allows you to get indicators of active and reactive power in the AC circuit.

The power value is an important indicator for any electrical device or mechanical device, since it is an indicator of the work that the equipment can perform.

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1 watt [W] = 0.001 kilowatt [kW]

Initial value

Converted value

watt exawatt petawatt terawatt gigawatt megawatt kilowatt hectowatt decawatt deciwatt centiwatt milliwatt microwatt nanowatt picowatt femtowatt attowatt horsepower horsepower metric horsepower boiler horsepower electric horsepower pumping horsepower horsepower (German) int. thermal unit (IT) per hour Brit. thermal unit (IT) per minute Brit. thermal unit (IT) per second Brit. thermal unit (thermochemical) per hour Brit. thermal unit (thermochemical) per minute Brit. thermal unit (thermochemical) per second MBTU (international) per hour Thousand BTU per hour MMBTU (international) per hour Million BTU per hour ton of refrigeration kilocalorie (IT) per hour kilocalorie (IT) per minute kilocalorie (IT) per second kilocalorie (thm) per hour kilocalorie (thm) per minute kilocalorie (thm) per second calorie (thm) per hour calorie (thm) per minute calorie (thm) per second calorie (thm) per hour calorie (thm) per minute calorie (thm) per second ft lbf per hour ft lbf/minute ft lbf/second lb-ft per hour lb-ft per minute lb-ft per second erg per second kilovolt-ampere volt-ampere newton-meter per second joule per second exajoule per second petajoule per second terajoule per second gigajoule per second megajoule per second kilojoule per second hectojoule per second decajoule per second decijoule per second centijoule per second millijoule per second microjoule per second nanojoule per second picojoule per second femtojoule per second attojoule per second joule per hour joule per minute kilojoule per hour kilojoule per minute Planck power

More about power

General information

In physics, power is the ratio of work to the time during which it is performed. Mechanical work is a quantitative characteristic of the action of a force F on the body, as a result of which it moves a distance s. Power can also be defined as the rate at which energy is transferred. In other words, power is an indicator of the machine's performance. By measuring the power, you can understand how much and how fast the work is done.

Power units

Power is measured in joules per second, or watts. Along with watts, horsepower is also used. Before the invention of the steam engine, the power of engines was not measured, and, accordingly, there were no generally accepted units of power. When the steam engine began to be used in mines, engineer and inventor James Watt began to improve it. In order to prove that his improvements made the steam engine more productive, he compared its power to the performance of horses, since horses have been used by people for many years, and many could easily imagine how much work a horse can do in a certain amount of time. In addition, not all mines used steam engines. On those where they were used, Watt compared the power of the old and new models of the steam engine with the power of one horse, that is, with one horsepower. Watt determined this value experimentally, observing the work of draft horses at the mill. According to his measurements, one horsepower is 746 watts. Now it is believed that this figure is exaggerated, and the horse cannot work in this mode for a long time, but they did not change the unit. Power can be used as a measure of productivity, as increasing power increases the amount of work done per unit of time. Many people realized that it was convenient to have a standardized unit of power, so horsepower became very popular. It began to be used in measuring the power of other devices, especially vehicles. Even though watts have been around for almost as long as horsepower, horsepower is more commonly used in the automotive industry, and it's clearer to many buyers when a car's engine power is indicated in those units.

Power of household electrical appliances

Household electrical appliances usually have a power rating. Some lamps limit the power of the bulbs that can be used in them, for example, no more than 60 watts. This is because higher wattage bulbs generate a lot of heat and the bulb holder can be damaged. And the lamp itself at a high temperature in the lamp will not last long. This is mainly a problem with incandescent lamps. LED, fluorescent and other lamps generally operate at lower wattage for the same brightness and if used in luminaires designed for incandescent lamps there are no wattage problems.

The greater the power of the electrical appliance, the higher the energy consumption and the cost of using the appliance. Therefore, manufacturers are constantly improving electrical appliances and lamps. The luminous flux of lamps, measured in lumens, depends on the power, but also on the type of lamps. The greater the luminous flux of the lamp, the brighter its light looks. For people, it is high brightness that is important, and not the power consumed by the llama, so recently alternatives to incandescent lamps have become increasingly popular. Below are examples of types of lamps, their power and the luminous flux they create.

• 450 lumens:
• Incandescent lamp: 40 watts
• Compact fluorescent lamp: 9-13 watts
• LED lamp: 4-9 watts
• 800 lumens:



• Incandescent lamp: 60 watts
• Compact fluorescent lamp: 13-15 watts
• LED lamp: 10-15 watts
• 1600 lumens:
• Incandescent lamp: 100 watts
• Compact fluorescent lamp: 23-30 watts
• LED lamp: 16-20 watts

From these examples, it is obvious that with the same luminous flux created, LED lamps consume the least electricity and are more economical than incandescent lamps. At the time of this writing (2013), the price of LED lamps is many times higher than the price of incandescent lamps. Despite this, some countries have banned or are about to ban the sale of incandescent lamps due to their high power.

The power of household electrical appliances may differ depending on the manufacturer, and is not always the same when the appliance is in operation. Below are the approximate capacities of some household appliances.



• Household air conditioners for cooling a residential building, split system: 20–40 kilowatts
• Monoblock window air conditioners: 1–2 kilowatts
• Ovens: 2.1–3.6 kilowatts
• Washing machines and dryers: 2–3.5 kilowatts
• Dishwashers: 1.8–2.3 kilowatts
• Electric kettles: 1–2 kilowatts
• Microwave ovens: 0.65–1.2 kilowatts
• Refrigerators: 0.25–1 kilowatt
• Toasters: 0.7–0.9 kilowatts

Power in sports

It is possible to evaluate work using power not only for machines, but also for people and animals. For example, the power with which a basketball player throws a ball is calculated by measuring the force she applies to the ball, the distance the ball has traveled, and the time that force has been applied. There are websites that allow you to calculate work and power during exercise. The user selects the type of exercise, enters the height, weight, duration of the exercise, after which the program calculates the power. For example, according to one of these calculators, the power of a person with a height of 170 centimeters and a weight of 70 kilograms, who did 50 push-ups in 10 minutes, is 39.5 watts. Athletes sometimes use devices to measure the amount of power a muscle is working during exercise. This information helps determine how effective their chosen exercise program is.

Dynamometers

To measure power, special devices are used - dynamometers. They can also measure torque and force. Dynamometers are used in various industries, from engineering to medicine. For example, they can be used to determine the power of a car engine. To measure the power of cars, several main types of dynamometers are used. In order to determine the engine power using dynamometers alone, it is necessary to remove the engine from the car and attach it to the dynamometer. In other dynamometers, the force for measurement is transmitted directly from the wheel of the car. In this case, the car's engine through the transmission drives the wheels, which, in turn, rotate the rollers of the dynamometer, which measures engine power under various road conditions.

Dynamometers are also used in sports and medicine. The most common type of dynamometer for this purpose is isokinetic. Usually this is a sports simulator with sensors connected to a computer. These sensors measure the strength and power of the whole body or individual muscle groups. The dynamometer can be programmed to give signals and warnings if the power exceeds a certain value. This is especially important for people with injuries during the rehabilitation period, when it is necessary not to overload the body.

According to some provisions of the theory of sports, the greatest sports development occurs under a certain load, individual for each athlete. If the load is not heavy enough, the athlete gets used to it and does not develop his abilities. If, on the contrary, it is too heavy, then the results deteriorate due to overload of the body. Physical activity during some activities, such as cycling or swimming, depends on many environmental factors, such as road conditions or wind. Such a load is difficult to measure, but you can find out with what power the body counteracts this load, and then change the exercise scheme, depending on the desired load.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question to TCTerms and within a few minutes you will receive an answer.