Instructions
When planning to calculate the horsepower of your car, use the Russian measurement system. In it, one “horse” is defined as 75 kg x m/s. Translated into scientific measurements, this means that one horsepower is equal to the power that is enough to lift a load weighing 75 kg to a height of 1 meter in 1 second of time. Also, " " is also translated into kilowatts. According to this translation, 1 hp. equals 735.5 W or 0.735 kW. But maximum speed, which can be developed by an ordinary horse, boiler horsepower.
Accordingly, the power values can be obtained by translation. So, for example, if the power of a car is indicated in kilowatts, then to convert it to “horses” you need to divide the indicated value in kW by 0.735 and get the number of horsepower in this car.
One of the most simple ways How to calculate it in horsepower (especially after tuning) is to go to a service or inspection point. There are special computer installations that determine the number of “horses”. To do this, you need to place the car on the device platform and press the gas pedal all the way. During the time the machine is running, the computer mechanism will take all the necessary measurements and tell you the result.
Just for fun, you can calculate not only the power of your car, but also your own. To make the calculations correctly, you need to measure the time (t) during which you can run a staircase of a certain height (h). Then the resulting values must be inserted into the formula: m x h/t. m here is your body weight. This comic test will help you calculate how resilient and fast you are in your movements. In addition, such funny calculations can be great entertainment for a family evening, when you can calculate its power for each family member.
Sources:
- What is 1 horsepower equal to?
Kilowatt (kW) is a unit of power, i.e. the relationship of work to the period of time during which it was completed. However, power can be measured in other units, and kilowatt can be easily converted to any of them by a simple multiplication method.
You will need
- Calculator or converter
Instructions
Often when solving, it is necessary to convert to units such as joules per second (J/s). This is very easy to do because one per second is equal to one . Therefore, to convert kilowatts per second, you simply multiply them by 10 to the third power, i.e. per thousand. For example, 5 kW = 5 x 1000 = 5000 J/s.
Another common unit of power measurement is horsepower (hp), but it is not part of the SI system. When converting to this unit, it is important to clarify exactly what horsepower is meant. In our country, metric horsepower is more often used. One kilowatt is approximately equal to 1.36 metric horsepower. And in the USA and partly in the UK, horsepower refers to electric horsepower. One kilowatt approximately corresponds to 1.34 electrical horsepower. There is also the so-called boiler horsepower. A kilowatt is approximately equal to 0.1 boiler hp. Thus, 5 kW x 1.36 = 6.8 metric hp, and also 5 kW x 1.34 = 6.7 electric hp. and 5 kW x 0.1 = 0.5 boiler horsepower.
The concept of “horsepower” has been known to all car enthusiasts for a very long time. Previously, all the hard work was done with the help of horses. Later, the first steam engine was created, which replaced them, and to determine its power, they resorted to comparison with the number of horses. Now horsepower, as a unit, is gradually being replaced by a new value of the SI measurement system - watt or kilowatt.
Recently, in most European countries, including Russia, it is customary to denote the power of vehicles not in the usual horsepower, but in units of kilowatts.
In this regard, it is very often necessary to find out the number of kilowatts that corresponds to a certain horsepower value and vice versa.
To convert from kW to l/s and vice versa, you can use the calculator:
One horsepower in our country, like in Europe, is 0.735 kW, or vice versa - 1 kW will be equal to 1.36 l / s (for calculations in whole numbers, many use the value 1.4).
For example, for a car with a power of 70 horsepower, the power in kilowatts will be 51 (70 l/s equals 70/1.36 or 51 kW).
Where did the value 0.735 kW come from?
As has long been customary, scientists obtained all values during experiments. Same with the value of 735 W.
It was taken as a basis that one horse would be able to pull a weight with a total weight load of 75 kg at a certain speed of 1 m/s. One horse, as already established, is considered to be 1 horsepower. When converted to watts and kilowatts, it is not difficult to obtain the following: 735W will be equal to 1 l/s.
If we round to whole numbers, we get that 1 l/s equals 0.74 kW.
Nowadays, in all passport documents for a car, namely in registration certificates, as a rule, two values are indicated at once - in kilowatts and the corresponding value in horsepower. This, in turn, is convenient and does not require additional translations.
So,
- in order to convert from the value - l/s to the value - kW, you need to divide the l/s value by 1.36 (a car with a power of 170 l/s corresponds to 125 kW).
- And vice versa, if a conversion from kW to l/s is needed, then the kW value must be multiplied by 1.4 (vehicles with a power of 88 kW correspond to 120 l/s).
For a short time, a horse can develop a power of 10 - 13 horsepower, but during normal rhythmic work it is just about one. Why was “horsepower” used as a unit of measurement for power? And how much is one horsepower?
The inventor of the steam engine, the Englishman James Watt (1736–1819), is “to blame” for this. He needed to clearly demonstrate to the public that his machine could replace many horses, and for this he had to somehow measure the work that the horse itself could produce per unit of time.
They describe such a story. James Watt proposed using steam power instead of horses in breweries. While observing horses, Watt noticed that a horse could drag a load weighing 14.774 kg over a distance of 0.3 m in 1 minute. Rounding 14.774 kg to 15 kg, he introduced the “horsepower” unit of power measurement. By comparing the performance of a horse and a steam engine using this unit, Watt convinced brewers to replace horses with steam, and as a result, the efficiency of the brewing process increased significantly.
This “herd” was put to rest in 1960 - the XI General Conference on Weights and Measures adopted a unified International System of SI (SI) units. In it, power is expressed in watts in honor of the same James Watt.
However, even now there is a concept of horsepower. At one time, Watt, observing a traditional source of energy - a horse, came to the conclusion that a barrel weighing 180 kg could be pulled out of a shaft by two horses at a speed of 2 mph (3.6 km/h). In this case, horsepower in English measures takes the form 1 liter. With. = 1/2 barrel · 2 mph = 1 barrel · mph (here the barrel is taken as a unit of force, not mass). The same in smaller units is 380 lbs at 88 ft/min. Rounding the calculations to pound-feet per minute, he decided that the horsepower would be 33,000 pound-feet per minute. Watt's calculations referred to horse power averaged over time. For a short time, a horse can develop a power of about 1000 kgf m/s, which corresponds to 9.8 kW or 33,475 BTU/h (boiler horsepower)
Units of measurement in different countries ah vary, and horsepower in Sweden is not exactly the same as in America, for example. In Europe, one horsepower refers to the power required to lift 75 kilograms one meter per second or 75 kilogram-force meters per second (kgfm/s). At the same time, in the USA, one horsepower means the power required to lift 550 pounds one foot per second, which corresponds to 33 thousand foot-pounds per minute. In Russia, as a rule, horsepower refers to the so-called “metric horsepower”, equal to exactly 735.49875 watts.
By the way, the photo at the beginning of the post is from the Library of Congress, taken around the 1890s at a logging site in Michigan.
In this way, timber was usually transported in spring and winter along a frozen path to the nearest railway or rivers. To make the movement of the loaded sleigh smoother, the road was watered, and the horses, as a rule, had special studded equipment on their hooves for better grip on the ice surface.
Automakers from different countries measure the power of their cars in different units. For what? You will find out the answer below
When reading an article about cars, rest assured, you will always come across this data. With which ones? With vehicle power data. Car engine power is one of the the most important indicators, relevant at any time, in any situation. From both practical and theoretical points of view.
Watt is a unit of measurement included in the SI system (International System of Units), which means how much power is required to perform 1 J of work per unit of time.
Mainly used by professionals as a more “correct” power indicator from the point of view of fundamental science. As a unit of measurement in the automotive industry, it is used mainly in the Southern Hemisphere, this is how it happened historically.
The method for measuring kilowatts of power in cars is basically by finding the amount of torque transmitted from the wheels on a dyno, then using this equation to make the calculations:
Kilowatts have become a modern measure of vehicle power output and perhaps in the future they will become a generally accepted worldwide measure. At least, if you look at any official data offered by automakers, you will definitely see units of kW of power of internal combustion engines on a par with horsepower.
Moreover, with the growing excitement around electric cars, the adoption of this form of measurement will become even more justified, since the amount of work produced by an electric motor is measured using kWh (kilowatt-hours), which determines how long an electric motor can produce a certain amount of power. energy, for example, to move a car.
Horsepower (hp)
Introduced by the “maestro” and part-time creator of productive steam engines - Mr. James Watt - this unit of power based on horsepower is somehow alive to this day, carrying the calculations of a brilliant engineer through the centuries. It is the main unit of measurement of car power in many countries, including Russia, and is used not only as a measurement of the power of an internal combustion engine in official documents for car models, but also for calculating taxation in the automotive sector, for example, calculating transport tax.
So what is horsepower (hp)? How did it appear and how is it calculated? How was her appearance connected with horses?
Scotland, inventor James Watt completed his first steam device, which could help hundreds of industrialists and artisans in their everyday work. And the engine seemed to be good to everyone, but how to explain this to ordinary people? The answer suggested itself; it was necessary to compare the work of the most common “power device” at that time (horse) with the work of a new car. No sooner said than done, Watt sat down to do the calculations.
CALCULATIONS AND COMPARISON OF UNITS OF MEASUREMENT
In most European countries, horsepower is defined as 75 kgf m/s, the power expended when uniformly vertically lifting a load weighing 75 kg at a speed of 1 meter per second with a free fall acceleration of 9.8 m/s.
In the International Metric System, the SI is officially measured in watts. 1 hp (metric horsepower) is equal to 735 W or 0.73 kW.
In turn, 1 kW is equal to 1.35 hp.
Moreover, in the measurement system in the United Kingdom, as well as in the United States, horsepower (hp) is equated to 745 W, which is why there is a slight discrepancy with European “horses”. Thus 1 hp. in the USA it is equal to 1.0138 hp. from Europe.
For example, the power of a 3.8 liter engineNissanGT-R is 570 hp, in kilowatts it will be equal 419
, in hp 577
units.
See also:
How James Watt introduced his steam engines and the concept of “horsepower” into use
Now no one knows exactly how strong the horses that took part in Watt’s experiments were, whether they were in their prime or whether they were old nags. However, several legends have survived.
According to one of which, a certain brewer, the first buyer of Watt’s steam unit, probably decided to hold a competition in order to reduce the price of the inventor’s machine. The horse in the brewing industry powered the water pump, and the brewer wanted to buy a steam engine instead.
In order to be sure to win, the dishonest industrialist chose the most strong horse and by manipulating the whip and other tools for increasing labor productivity, he squeezed maximum efficiency out of the poor animal. In response to the challenge, James Watt, using his machine, exceeded the work performed by the horse, according to some data, by 1.5 times, which served as a model for accepting a metal device that ran on water vapor.
The second legend, on the contrary, tells us that Watt himself slightly “twisted” the calculations in his favor. He needed this in order to convince the intractable owners of coal mines to switch from draft horses to steam engines. In the 18th century, coal from their mines was lifted using horses using ropes through a pulley system. Having calculated the productivity of the average horse, Watt applied a coefficient by multiplying the resulting number by 1.5, due to which his machine easily outperformed any horse doing the same work.
Since horsepower has spread significantly throughout the globe due to the ease of calculation and clarity for users, various types(definitions) horsepower: metric horsepower, mechanical horsepower, boiler horsepower, electrical horsepower. And water horsepower.
Perhaps in some articles and news, both foreign and domestic, you have more than once encountered incomprehensible abbreviations, for example: nhp,rhp, bhp, shp, ihp, whp. What do they mean?
Nhp orrhp,Nominalhorsepowerratedhorsepower- useful power, used to estimate the power of steam engines.
bhp,Brakehorsepower- effective power in hp, the power “removed” from the crankshaft of an internal combustion engine, does not take into account the power loss from the gearbox and transmission of the car.
Shp,Shafthorsepower- engine shaft power is the power supplied to the propeller shaft, to the turbine shaft or to the output shaft of the automobile gearbox. Gross
Ihp,Indicatedhorsepower- indicated power in hp, this is the theoretical power of a piston engine, determined by the sum of power from the crankshaft, effective power, and energy spent on friction.
In our metric system, the term “horsepower” appeared thanks to the English inventor James Watt. One horsepower means power, not strength. This physical quantity denotes the ratio of work performed uniformly in a certain period of time. The scientist observed the work of horses on coal spears. The animals pulled heavy baskets of coal out of the mine using a block device. James Watt measured the total weight of the load they removed and the height to which it was raised over a certain time.
This unit of power was eventually called "horsepower" or "horsepower" in English. Later it began to be designated as “hp”.
Horsepower and kilowatt
In October 1960, by decision of the XI General Conference on Weights and Measures, the Unified International System of SI Units was adopted. At the same time, horsepower officially became a unit of power, generally accepted throughout the world, and therefore the power of automobile engines is precisely in these units.
1 horsepower is equal to 736 watts or 0.736 kilowatts.
And vice versa - 1 kilowatt is equal to 1.35 horsepower. Accordingly, 1 watt is equal to 0.00135 horsepower.
