Comments by "GH1618" (@GH-oi2jf) on "What Is Horsepower u0026 Why It's A Dumb Unit - America vs Metric" video.

  1. “Kilogram-force” is the force on a one-kilogram mass under standard gravity of 9.8 m/(s squared). It is is a useful term, as is “pound-mass.”
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  2.  @DaveyGa  — Yes, we know that US Customary units are defined in terms of metric units. The United States adopted metric units in 1866, and standardized the conversions long ago. This is very old news.
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  3.  @markmuir7338  — Don’t let me catch you using degrees for angles!
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  4. That’s not the reason. It is just a matter of tradition.
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  5. Hp isn’t about horses at all, it’s about quantifying power. A horse driving a mill just happened to be convenient for the purpose at the time. We (in the USA) use Watts also, but we use the two units in different ways.
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  6. We do not use Imperial units in the United States. We use US Customary units, which are a little different. This has been said a hundred times, but you haven’t been reading the comments.
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  7. “Brake” HP
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  8. Yes, we use Hp to denote the capacity to do work — the peak (continuous) power. We use watt-hours to measure the energy consumption. Engines and motors usually operate well below their peak power.
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  9. It would be interesting to put the unit to a test. Find a horse-driven mill typical of those used in Watt’s time. A one-Hp electric motor should be able to drive the mill at the rate a walking horse would.
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  10. US carmakers give power specs in both HP and kW. Take your pick.
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  11. Take two 5-grain aspirin.
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  12. They think their power is underestimated.
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  13. “motor n. ...; an engine, esp. that of a vehicle. ...” from The New Shorter Oxford English Dictionary
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  14.  @theo7709  — We don’t hate the metric system. Some individuals might.
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  15. The United States does not use Imperial units.
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  16. Actual engineers don’t get worked up over units. It’s the amateurs, mostly, who get excited.
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  17. Not the same. A Newton is the force that accelerates a 1kg mass at 1m/s^2. Kgf is force on a 1kg mass in standard gravity, which is 9.81m/s^2.
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  18. We call them US Customary units. We do not use Imperial units in the United States. Some Imperial units differ from their US counterparts.
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  19. It’s hard to get a good understanding using vehicles with internal combustion engines, because there are so many complications. For example, my truck is rated 200 HP at 6300 RPM, but I never rev the engine anywhere near 6300. Then there is gearing, wind resistance, tire drag, and so on.
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  20. Ironically, we commonly use hp in the USA to rate electric motors.
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  21. Your left arm is redundant.
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  22. It isn’t really about horses, so it doesn’t matter. Anyway, a more powerful horse probably wouldn’t walk much faster, it wouldjust be easier for the horse to pull the load.
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  23. American engineers are practical people. We use whatever suits our purpose. I’m sure Jason knows very well what Newtons are, but worked it out in the manner that was most convient, Precision does not depend on units.
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  24. Yes, and also electric motors. If you have a shop with powered equipment, you need to pick a suitable motor for each. The motors are rated 1/3, 1/2, 3/4, or 1 hp, for example.
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  25. The international pound is defined in relation to the kg, so it is also a mass unit.
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  26. A car is not the best thing to use for an example, because it develops maximum horsepower only at high rpm. Then there are factors like traction that complicate matters. It would be better to use a 150 KW electric motor.
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  27. Everybody knows electrical units are universal. Except that electric AC motors are still rated in Hp.
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  28. It is a convenient unit for large systems. If it weren’t convenient, people wouldn’t use it.
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  29. Ok, I don’t get the joke. As an engineer, I know that Hp isn’t actually about horses.
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  30. The “ton” is still a useful unit to use for air conditioning. It’s a good example of how special units can be used for convenience in special applications. There is no reason to belittle the concept. By the way, it corresponds to 12,000 BTU/hr.
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  31. Actual engineers are practical people. Most of the complaining comes from laymen.
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  32. No, 1 kgf is 9.8 Newtons (approx.)
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  33. That’s not hypocrisy. Hypocrisy is do (or not do) something while pretending the opposite. There is no pretense here, so no hypocrisy.
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  34. It is “kilogram-force” or kgf, a unit.
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  35. If you prefer, you may use an engineer’s scale, which is in feet divided into tenths and hundredths. There is no law against it.
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  36. Short answer: Power is the rate of doing work. One horsepower is the size of the most powerful in-sink garbage disposals for residential use.
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  37. Not really. Hp has been used for a long time, so it is just customary. For electric motors, we use both. Watts are used for energy consumption (Watt-hours). Horsepower is used for power output.
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  38. We could look up the conversion, but it isn’t necessary. Units are optimized for use in particular applications. Every professional HVAC person has an idea what a “ton” of cooling capacity is. Every homeowner planning a kitchen remodel knows that a 1 HP disposal is more powerful than a 1/2 HP disposal.
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  39. This is disingenuous. Everybody knows the “foot” as a unit is not anybody’s foot in particular, but is a well-defined distance. “Foot” is just the name and it’s a convenient name.
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  40. “brake” Hp
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  41. Wrong. He just used it.
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  42. That’s why there are graphs of power and torque against rpm.
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  43. It would have be geared down substantially, so would take more than 10 minutes to lift that weight one foot. The only difficulty is that you have to overcome friction in the pulley or other gearing mechanism, so it doesn’t just scale up to arbitrarily high weights.
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  44. The Hp was defined before the Watt, so it is what it is.
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  45. It is not strange that altitude for aircraft is in feet. Anyone who thinks that hasn’t put much thought into the problem. It is simplistic to assert that one set of units should do for all situations without working out the implications for each situation.
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  46.  @nirfz  — It isn’t one Newton. There’s a conversion factor, which is why he used that form.
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  47. The attempt by the EU to force British pubkeepers to drop the pint was the first sign of the fascist nature of the EU and probably helped start the Brexit sentiment.
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  48. If you can’t handle any units easily, you are not cut out for engineering.
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  49. What is the size of the drive for metric sockets in Europe?
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  50. No, it was named in his honour.
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  51. Completely wrong. At the time of the settlement of the American colonies, the metric system was not well established anywhere. We used units that originated in Britain, mostly.
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  52. Since the subject is units in the context of automobiles, I’ve been wondering what the specification is for the fitting on a driver for sockets used by European mechanics. Is it completely different from the US fitting, which is square in (typically) 1/2 or 3/8 inch sizes? Is it similar but in mm sizes? Or is it the same? If the same, what is it called in various European countries?
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  53. Why is that unfortunate? You could say “USC” or just “US.” Product packages for liquids might be marked “US fl oz” for example. In olden days, we called them “English” units, but that is informal usage. “Imperial” is just wrong.
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  54. Falling in love with a system of units seems a little deviant, if harmless.
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  55. Go ahead, change.
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  56. Sometimes we do. Spark plug torque is specified by the manufacturer in both lb-ft and n-m. You can buy a metric torque wrench from an American wrench company. We in the USA are tolerant of differences in units.
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  57. One Hp is 0.746 kW. It’s easy to look such things up.
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  58. It’s an easy conversion to learn, though. One horsepower is about 3/4 of a kiloWatt.
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  59. All energy in whatever form is equivalent. This is a fundamental principle of physics that takes some getting used to. For example consider that you might have a diesel engine used to drive an electric generator. The engine has some maximum horsepower that it can produce. That limits the kW that the generator can produce.
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  60. It has more to do with the mill than the horse. He probably looked at typical mills designed to be driven by a single horse. They would probably have been similar in design, because experience would have led mill builders to a standard design. He could easily have measured the force required to turn one.
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  61. Kgf isn’t a standard unit, but it certainly exists and Jason did use it. It’s his prerogative to use whatever units suit his purpose.
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  62. Exhausting? Can you express the work in knowing that fact in Joules?
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  63. Not the same unit.
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  64. In the United States, we learn arithmetic at an early age. While odd fractions of 32nds do exist, they are not common — about as common as half-mm sizes.
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  65. The fallacy is that before you get anywhere near having 700 horses, most of the mass is horses, so most of the work is moving the horses. Another fallacy is that horses can only go so fast. More horses won’t go any faster.
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  66. Horsepower is useful for comparison of modern engines to earlier ones. The classic Chevrolet “Blue Flame” straight six was rated at 136 Hp (150 for the Corvette). My modern Chevy pickup is rated at 200 Hp with four cylinders and a smaller displacement, naturally aspirated. Internal combustion engines have come a long way.
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  67. No actual scientist or engineer is disturbed by such things, only little smatterers, to use Newton’s term.
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  68. kgf is force. It is the weight of a 1 kg mass under standard conditions.
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  69. My sentiments (as an engineer) exactly.
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  70. The United States uses SI units, although not exclusively. The US adopted the metric system in 1866 and has contributed to the development of S.I. since 1875.
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  71.  @waynehobbs5175  — We use US Customary units, not imperial. We are bimetral. We use USC and SI units. That’s why I wrote “not exclusively.” Get it?
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  72. The name is “gasoline.” You can’t stop people from using shorthand. I’m pretty old so have been buying “gas” for quite a long time. I have never in my life met someone who was confused by the dual meaning of the word. When I say “I need gas,” nobody thinks I need to put air in my tires. People are smarter than you think.
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  73.  @somedude9431  — That’s a good point. There are always differences in local use of a common language. Nobody is right or wrong. In the USA, vehicles which run on propane are rare. We do use it for cooking and heating, however.
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  74. How about you respect the freedoms of others to use whatever units serve their purpose?
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  75. The Joule is a unit of energy, not power.
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  76. We do not use Imperial units in the United States. We left the Empire before Imperial units were defined.
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  77. In the United States, we ddo not use Imperial units anyway. They were introduced after the USA left the Empire.
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  78. Jason probably used kgf because it was more convenient in the context of his calculation. He knows perfectly well what a Newton is. Americans, even many of those who like metric units, are practical people. We don’t get hung up on such things.
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  79. He’s American. We don’t use Imperial units in the United States.
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  80. It isn’t actually about horses.
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  81. Yes, units are arbitrary.
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  82. That is not the kind of teacher we need in the United States. Anybody teaching science ought to know that units are arbitrary. The science is not in the units, but in the relationships between things.
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  83. I’m an engineer also. While not the standard unit, it is nevertheless legitimate. If he finds it convenient, he may use it. It is easily converted to standard units.
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  84. US Customary units are not “random.” They are as systematic as any system of units.
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  85. Every unit can be derived from other units. We have units of power because it is a useful concept.
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  86. No, we don’t expect the world should adapt to the US. We use metric units to manufacture items sold in other countries. But if you come to visit, our road signs use miles.
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  87. Of course, we also use Watts. In the USA we may use whatever unit fits the situation.
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  88. It isn’t the law. I (in the USA) would write 5 Nov 2020, unless instructed otherwise in a particular situation. Any system which uses only numerals has ambiguous cases.
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  89. No, actually the computers did calculations in metric units. Certain parameters which were displayed to the astronauts were converted to Customary units.
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  90. — Many thousands of people were involved in projects Mercury/Gemini/Apollo. The computer algorithms used metric units. For example, in the document “APOLLO NAVIGATION, GUIDANCE, AND CONTROL SYSTEMS A PROGRESS REPORT” (MIT 1969), you will find both metric and US units. See also: The Apollo Guidance Computer: Architecture and Operation, by Frank OBrien. “... the units employed internally in the AGC are exclusively metric, yet human factors demand that the crew uses English units.”
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  91. Our units may be peculiar, but they are not vague.
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  92. Nope. KenWorth trucks are the best.
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  93. It shouldn’t. Kg-force is a convenient unit. If he chooses to use it, it is his business. You may do the math your own way. I’m guessing you don’t even know what kgf is.
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  94. There are more than five, but a vocabulary of five words is not large. How much can you say with only five words? I’ll bet you know many more words than that, because you have used more than five in just one comment.
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  95. We use the international foot in the USA today. The US survey foot is obsolete. I don’t even know what the third one is.
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  96. Tell that to members of the World Champion US women’s soccer team.
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  97. Neither is an indication of brightness.
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  98. It’s interesting that my engine is marketed as being 2.5 l, but 150 ci is a more accurate figure.
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  99. People the world around often use “America” to mean “United States of America.” It’s not our fault.
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  100. Torque is a force acting at a distance to rotate the object being worked.
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  101. The United Stated adopted the metric system in 1866.
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  102. In the United States, you are free to use whatever units you please. However, you may not demand that I use the units you prefer. Both US Customary and metric units are legal in the USA.
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  103. Not likely. Large countertop microwave ovens are on the order of one HP.
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  104. There is a great deal of metric usage in the United States. Medicine is metric. Nearly all hardware on automobiles is metric. Wine and spirits are in metric bottles. We let individuals and individual industries choose what they prefer.
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  105. Oh, please! Whinging is no way to get ahead in your career.
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  106.  @OtakuDude93 — My feelings are not hurt. I ( a Usanian) studied science and engineering and used metric units without complaining about it. One uses the notation that is customary in whatever profession one chooses. If you are having difficulty learning your profession, perhaps you are choosing the wrong career. Or, if the school is not using current conventions for that career, perhaps you are in the wrong school. Don’t blame it on Usanians generally.
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  107. Yes. This is how actual, working engineers look at these things. Complaints are mostly from laymen who just don’t want to be bothered learning something different than what they are used to.
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  108. The United States adopted the metric system in 1866. You are free to use it at any time. You don’t need to be taught it, because it is trivial. If you understand any system of units you can learn another system of units on your own.
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  109.  @Redtooth75  — Exactly. It was not Watt’s objective to quantify the maximum power a horse could muster.
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  110. We don’t use horses. James Watt used a horse to set the scale for units of power. Today, it doesn’t have anything to do with horses. It is just a historical curiosity.
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  111.  @quelorepario  — Of course we use the Hp unit, but it doesn’t really have anything to do with horses. The unit was derived from an actual horse application as a means of relating it to human experience. On e the unit was set, the horse is no longer important. It’s about power, not horses.
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  112. You must take into account the hp to weight ratio and other factors.
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  113. Nobody in the USA is confused by light bulbs being designated in Watts. At least we weren’t until the introduction of LED lamps. And we don’t think of them as being SI units, hence something different. Only scientifically trained people know what SI is. Watts are the customary unit for rating lamps in the USA, as everywhere else.
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  114. We are not embarrassed. We wonder why some Europeans get their panties in a knot over units.
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  115. Force relates directly to acceleration. Torque is force applied to a rotating object. Beyond that, it gets complicated, because power and torque curves are not linear and because you have to shift gears to extend the operating range.
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  116. You are free to use whatever units you like. Both metric and US Customary units are legal in the USA.
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  117. There is no need to be consistent. What matters is that a unit be useful and convenient. If it is convenient for you to think of electric power supplies in Hp, go ahead. It’s a free country.
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  118. In the USA the kW of power is widely used for electricity, but not often for mechanical power.
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  119. Enough to buck most people off, if he wants to.
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  120. Of course it’s silly, so we don’t do that. We use Hp where it is convenient, for example shop motors. These are typically 1/2, 3/4, or 1 hp, familiar to anyone who uses electric motors in that power range.
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  121. No, we just think “watts” is for electricity.
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  122. Hp is just the name of the unit. Its relation to actual horses is only of historical interest. Watt needed to set the magnitude of the unit to something familiar, and a mill driven by a single horse was fairly common, so familiar. That’s all there is to it. It isn’t really about horses, it’s about power as a quantifiable concept.
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  123. No, we don’t all agree. In the USA we typically torque our wheel nuts to a specified pound-feet (I prefer to say foot-lbs). I don’t see anything wrong with that. Units are arbitrary. If I only had a metric torque wrench available, I would convert to the equivalent metric value and use that.
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  124. Simple question: Why worry about what units someone chooses to present their data?
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  125. The diagram is simplified. You would need to gear down the mechanism to get mechanical advantage. Then the horse could lift the weight one foot by traveling several feet in one second.
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  126. Hp is not force, it’s power.
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  127. It isn’t, though. The Hp unit isn’t about horses, it’s about power. The unit was based on a typical work horse driving a typical one-horse mill.
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  128. That’s not true. I have engineering degrees. I know very well what Watts are, but I have no problem using Hp as applied to vehicle engines or electric motors. In the case of electric motors, it is useful to have two representations of power because the power varies with load. A rating of one hp indicates the capacity of the motor. KW-hours are what we meter to charge for the energy actually used.
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  129. A 100 Watt lightbulb is about 0.134 Hp.
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  130. A practical mnemonic!
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  131. Actually, we use both. Individuals tend to use customary units for everyday things, but some industries switched to metric units because international trade requires it. For example, wine and spirits producers have been using the 750 ml bottle for a long time. US consumers don’t care. The unit for a bottle of wine is the “bottle.”
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  132. It isn’t an obsession, just a convience. It is convenient to classify electric motors by Hp, particularly in the neighborhood of one Hp. Anyone with stationary shop tools, such as a table saw, needs to know the size of motor needed, and Hp is a convenient metric to use.
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  133. In the United States we have free speech. If it suits him to state force in a different unit, he is free to do so. I like this engineer’s practical approach.
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  134. Nearly the entire world does.
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  135. Yet anybody studying physical sciences learns very early of the equivalence of energy in its various forms. It is a fundamental idea which must be understood to understand any subject based in science.
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  136. One hp is about 3/4 Kw, so 450 Watts.
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  137. That’s not the reason we use Hp, though. It’s just tradition.
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  138. The time in seconds is just a scalar number like any other. To cube a number, you multiply it by itself, then multiply by the number again: s*s*s, where * means multiply.
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  139. More likely, he just used a typical horse of the type that was used for turning mills.
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  140. The unit is lb-ft. (multiplied, not subtracted!)
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  141. We do use the Watt unit in the USA. We use Hp and Watt for different purposes.
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  142. SI is a particular set of units defined by international treaty. “Metric” is a broader term.
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  143. That’s not true. The definition of the kg has been changed recently to remove the dependence on a physical object as a reference standard. That was the last one, because meter and second were easy.
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  144. Not true. It is just traditional, that’s all.
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  145. US cars are also rated in KW, but nobody pays any attention to that number.
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  146. It isn’t about horses.
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  147.  @AndrewF970  — Not if it is written lbm (pound-mass). One lbm is the mass that produces one lbf (pound-force) at standard gravity.
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  148. Doesn’t matter, though. It isn’t about horses.
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  149. We also use horsepower to rate small electric motors. A disposal unit under a sink might be 1/2, 3/4, or 1 HP.
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  150. How far does a horse walk in one second? Almost six feet, so it is actually pulling less than 100 lb. That isn’t much for a horse.
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  151. He is allowed to have opinions.
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  152. That’s not true. It’s just traditional. People don’t change units without a reason, unless they are forced to.
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  153.  @MaximKilligan  — No, we are not after Joules. Physicists use Joules, but KWH is a more convenient unit for a household energy meter. It would have to be MJ, anyway.
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  154. It is 550 ft-lbs per second. Only three variables. I’m not sure how engineers measure the power curve of an engine, though. There are practical considerations.
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  155. Almost 3/4 of a kWatt. You could easily have looked it up, or just read the comments.
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  156. Yes, except that fractions are studied in 3rd and 4th grade, according to my teacher spouse.
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  157. Ft-lbs is energy (or work), not force.
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  158. You are being facetious.
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  159. But those parameters are not constants. They vary with rpm. They may not be given at the same rpm. To get a good comparison, you need to look at the curves.
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  160. KWH and miles are both common units in the US, so it makes sense to us. If you want to use km, it’s a trivial transform.
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  161. Jason is a practical person, not a missionary, it seems to me.
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  162. Machinists can divide an inch to a ten-thousandth.
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  163. The Newton is the standard unit for force, nevertheless kgf is a perfectly well-defined unit of force. He uses it here because it is convenient for his purpose. Like all good engineers, Jason is practical.
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  164. It’s the same as 0-60 mph, for practical purposes. Everybody who is paying attention knows that conversion, because we have had both scales on our speedometers for many years.
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  165. Probably. They sell their products world-wide.
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  166. We use it for electricity billing because it relates easily to a familiar electric-powered object, the light bulb. Everybody knows what a 100W lamp is. If you light it for ten hours, you have consumed 1KWH of electric energy. Choice of unit is always about convenience, not about satisfying some abstract idea of purity in measurement.
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  167. It isn’t about horses.
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  168. Nobody cares how many inches are in a mile. When you do a calculation like that, you are missing the point of having different units for different scales.
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  169.  @pkt1213  — But it doesn’t illustrate the point you intended. Your example merely illustrates that you don’t understand the reason that there are several different units for distance in the US Customary system.
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  170. No. It was a meaningful unit at the time he developed it, even though it seems arbitrary today. It certainly isn’t random.
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  171. It was proposed by C. William Siemens and adopted in 1908 by the International Conference on Electric Units and Standards, meeting in London.
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  172. Jason used kgf, so your assertion is contradicted. It is used, it just isn’t a standard unit. The international pound is defined in term of kg, but one can use lbf or lbm, depending on the situation.
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  173. Go ahead, switch. It’s a free country.
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  174. I don’t if Zen addresses this situation, but a practical person would research the subject online to decide for himself what was needed. When I look up “diesel generators” I find that they don’t even go down to 3 KW. The smallest diesel Generac is 5 KW. Generac makes a gasoline-powered 3500 Watt generator. Maybe that will do.
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  175. As has been noted, all units are arbitrary, at the outset.
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  176. I agree that we always thought of pounds as force, but the pound has been defined relative to the kg for quite a long time. As a practical matter, it doesn’t make much difference. Rocket scientists have to use newtons and kg, but ordinare people aren’t thinking about physics in the supermarket.
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