What is horsepower and how much is it equal to?
Most of us have a laid back attitude when it comes to painting a picture about ourselves. One of these very important and widely used concepts can be horsepower. That all members of society are dealing with or have heard of its name, but the vast majority of them do not know the meaning of the word or its origin, so we want to talk briefly about the origin and concept of "horsepower" Have.
In the not-so-distant past, horses were the main source of power on farms. Before the advent of tractors, horses were used to carry a variety of loads. If farmers were to still rely on horsepower to produce food, we would probably need 20 times the current number of horses on Earth.
Almost all of us today know that the term horsepower refers to engine power. Power can be defined as the speed of doing work. This quantity is calculated as the ratio of the work done to the duration of that work.
The unit of measurement of power (both mechanical and electrical) is the watt. One watt equals one joule of work done per second. Each joule of energy is defined in meters per kilogram per second.
What is horsepower?
The term horsepower was coined by James Watt (176-1886). He is best known for his work to improve the steam engine. We also remember him whenever we talk about 500-watt light bulbs.
The story begins when Watt worked in a coal mine with horses lifting coal and wanted a way to talk about the power of each of these horses.
He found that, on average, a mining horse could do 22,000 pounds (about 40 kilojoules) of work per minute. He then increased that number by 50 percent. And it put 1,000 horsepower (about 25 kilojoules) of energy per minute.
It was an optional unit that, centuries later, is now used in cars, lawn mowers, chainsaws, and some vacuum cleaners.
The concept behind horsepower is as follows: According to Watt, a horse can work at 2,000 pounds per minute.
So consider a horse pulling coal from a mine, a horse that has one horsepower can lift 50 pounds (50 kg) of coal in one minute by 100 feet (50 meters) or 3 pounds ( (15 kg) in one minute 3,000 feet (100 meters).
Of course, it is worth mentioning before James Watt; A clever and genius engineer named Thomas Savry made brief references to the issue of horsepower in his book The Friend the Miner. He said in this book that:
Suppose the water pump draws water with a force equal to that of two horses working together at the same time. In this case, to do this continuously, you need to keep 10 or 12 horses on your farm.
Therefore, this engine runs at 10 to 12 horsepower. In the future, larger engines can be designed that can handle eight, 10, 15, or even 20 horsepower.
But back to James Watt, he found that, on average, a mining horse could do 22,000 pounds (about 40 kilojoules) of work in one minute. James then increased that number by 50 percent and put the horsepower at 3,000 pound-feet (about 25 kilojoules) of energy per minute. This unit actually represents one horsepower.
You can consider different combinations of weights and shifts per minute, and you will have one horsepower until you multiply them by 3,000.
You might think that it is not possible to put 3,000 pounds (35 tons) of coal in a bucket and ask the horse to move it 3 feet (50 cm) in one minute because the horse cannot move such a heavy load.
You may also think that it is not possible to put 3 pounds (750 grams) of coal in a bucket and ask the horse to move it 3,000 feet (50 km) in one minute.
Because in this case the speed of the horse should be 575 mph (601 km / h) which is not possible.
If you have read how spools and ropes work, you know that with a set of spools you can change the ratio of displacement and weight. So you can make an arrangement of spools. In a way that is compatible with the proper speed and load of the horse and it does not matter what load is in the bucket.
Horsepower can be converted to other units:
One horsepower is equal to 766 watts. So if we connect a horse to a wheel to turn it, with that wheel, an electric generator can be used that produces 76 watts of power.
The energy produced by one horsepower per hour is 25.55 BTU, which is the energy required to raise the temperature of one pound of water by one degree Fahrenheit.
A BTU is 3055 joules, or 252 grams of calories or 0.252 calories. A horse probably burns 60 calories per hour.
If you want to know the power of a motor, you have to connect the motor to a dynamometer. It puts a load gauge on the motor and measures the power that the motor produces against the load.
The idea of how the power meter works can be understood as follows: Imagine you start the engine and press the accelerator pedal without a load on it. In this case, the engine spins so fast that it breaks down. .
This is not convenient, so with a power meter you put a load on the engine and measure the load that the engine can withstand at different speeds. You have to connect the power meter to the engine, accelerate it and change the load on the engine with the power meter to keep the engine speed constant at, say, 7000 rpm.
And in this round, you record the load that the engine can withstand. Then increase the load to reduce the engine speed to, say, 6500 and re-record the load corresponding to this speed. And so on.
You can also do the same from 500 and 2,000 rpm. What the power meter measures is torque, and to convert it to horsepower, you have to multiply the torque by the engine speed.
Draw a power diagram:
If you plot the power of an engine (in horsepower) versus engine speed, what you end up with is the engine power curve.
Such a diagram shows that each engine has a maximum power (engine speed at which the engine output power is maximum). Also, a motor has a maximum torque at a certain speed. You usually see something like this in magazines and publications:
rpm 6500 hp @ ،20, rpm5000lb-ft @ ٩0 (for 1999 Shelby Series 1)
When an engine is said to have low end torque, it means that the maximum torque occurs at relatively low engine speeds (for example, 2,000 or 2,000 rpm).
Another thing that can be seen in the power curve of a car is where the maximum power occurs. When you try to accelerate quickly, you want to keep the engine close to the maximum power and therefore you reduce the gear to increase the engine speed. And get as close to maximum power as possible.
When you want to start moving behind the red light, you accelerate to increase the engine speed and get closer to maximum power, then release the clutch to transfer a lot of power to the wheels.
Power in high performance vehicles:
A high-performance car is called one that has a lot of power relative to its weight. The heavier the weight, the more power is needed to accelerate the car. For a certain power, the weight must be reduced to increase the acceleration.
How to calculate horsepower:
To calculate engine power in internal combustion vehicles, not electric motors, first calculate the maximum engine output torque due to friction reduction at low speeds with special test devices connected to the engine crankshaft output. Then multiply the number obtained by the engine speed and divide by 5252.
For example, the power of a Pride or Samand engine, at 4200 rpm, is 300 Nm of torque. It comes to be called 240 horsepower.
Power = Torque X engine speed /
What is torque?
The effective factor in rotating any object around an axial axis is called torque. Torque is a physical quantity in rotational motion that depends on the magnitude of the force and the direction and location of the force effect. Torque is a vector quantity and its unit in the International System of Units is the Newton (N.m.).
Or in another definition, it can be said that torque is the force that causes rotation in the body. This force is applied perpendicular to the axial distance from the center of the object and causes it to rotate. It's like if you put a wrench on a screw and apply force to it, the screw starts to rotate.
But if the same force is applied directly to the screw because its arm distance is zero, it does not affect the screw. If a force is applied to an object in the direction of its axis or center, the torque is zero.
In other words, the torque from the product of the external vector of the location of the point of effect of the force on the vector of the force acting on a point is called the torque of that force (around the origin). The direction of the vector is determined using the law of the right hand.
The difference between torque and horsepower
Power or torque, which is better?
It is not possible to say which is better, because these two forces and torque must be next to each other, but you should know that high power cars have better acceleration and higher speed. But high-torque cars have higher initial acceleration, which can be used optimally at low speeds, which has a great impact on fuel consumption.
Why are high-torque cars faster at initial acceleration?
The primary gears are larger and pass a lot of torque, so when the torque is high, all of it is directed to the output in the first gear. And it makes the initial acceleration faster, but after a moment, the high-powered propellers turn around and move forward.
The most important differences are the torque and horsepower of the car
Why are high power cars used in racing?
Maximum torque is generally achieved at low revs, so trucks need more torque to pull loads, but more speed is needed in racing because higher-powered engines can reach faster engine speeds.
The automotive industry
Torque is the product of force in distance, it is necessary to use a wrench to understand this. When we apply force to the wrench, this force travels the distance from the handle to the end of the wrench and tightens the screw by creating torque.
Torque or horsepower, which is more important for the car?
In the combustion cylinder, it produces a force to move the piston downwards, causing the crankshaft to drop to a certain extent. The term "torsional units" is used at this time because the piston and crankshaft generate torsional force.
Horsepower is the speed at which work is done and is the product of torque at engine speed. The engine produces more power when the crankshaft spins faster with a constant amount of power. A car with more horsepower than torque will be a fast car.
Familiarity with the two concepts of horsepower and torque, you will find that the old concept that "horsepower is the speed at which you hit the wall and torque is the amount of pushing back the wall" is wrong.
What is the difference between car torque and horsepower?
Both engines offer the same speed, but the diesel engine accelerates faster, which is why low torque is important for better acceleration.
More torque does not mean that one car is moving faster than another. For example, the F250 has 925 lb-ft of torque, but the Honda S2000 has 162 lb-ft of torque, but the Honda S2000, although less horsepower, moves faster due to the power-to-weight ratio.
For acceleration, the power-to-weight ratio is more important than the weight-to-torque ratio, so the 2800-pound Honda reaches 100 km / h in 5.7 seconds, while the 83 8300-pound Ford reaches 100 km / h in 6.9 seconds.
Horsepower in Automotive Mechanics:
Where do cars get their power from?
Very small explosions that occur thousands of times per minute inside the engine produce power. The more efficiently and efficiently the engine can burn fuel in the shorter time, the more energy it can produce. Power is the speed of energy production.
This definition is exactly the concept of power, that is, the more energy we can produce in less time, the more power we have. Power is measured by a very old unit called a horsepower. If your car is said to have 150 horsepower, think of it as a carriage pulled by 150 invisible horses.
How many watts is equal to horsepower?
Since then, the title Horsepower has been used and continues to this day. The impact of James Watt's work was so great and original that not only the comparison he made became the source of the work and the naming. Rather, his own name, the watt, continues to be used as another unit for measuring power. Horsepower with the abbreviation HP, which stands for Horsepower.
How many watts is equivalent per horsepower?
You may have bought a device that displays its power in watts, but you would like to see this in HP. In fact, each horsepower is equivalent to 745.6 watts, and naturally every 745.6 watts is one horsepower. So horsepower is a larger sheriff's unit.