Eli5: According to Google a horse at peak power produces 15 horse power…. so what animal at peak power would produce 1 horse power?

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Question is as the title suggests really.

Essentially I went on a watt bike the other day and my friend said I nearly produced one horse power. So obviously I then googled how much horse power a horse produces, and then when I found out it is more than one I was curious as to what animal produces one horse power and what we should change the measurement ‘horsepower’ too.

Also, I don’t think I’ve ever typed horse and horse power so much in such a little space

In: Mathematics

5 Answers

Anonymous 0 Comments

I get your question but still confused. A a horse at peak can do 15 horsepower, but 1 horsepower was done when not at peak power.

That’s like saying to find an animal who runs as fast as humans walk as “walking speed” is slower than our running speed.

Anonymous 0 Comments

Humans and horses actually. Depends what you’re looking at.

An healthy human can output 1.2 hp briefly or 0.1 without getting tired.

A horse can output 15 horse power briefly but the general recommendation was to make your farm horse work only as hard as what would be 1 horse power, sustained.

If you were at max output all the time you would get exhausted very quickly. Engines don’t get tired.

Anonymous 0 Comments

> I was curious as to what animal produces one horse power

Well, it looks like you proved a human does! And probably other animals of similar strength, like a husky pulling a dogsled.

> and what we should change the measurement ‘horsepower’ to.

Horsepower doesn’t refer to the peak output of a horse, but rather the sustainable output of a horse over a period of hours. A horse can output 5 HP for a few moments, or 1 HP consistently. A human can output 1-1.2 HP for a few moments, or 0.1 HP consistently.

If we’re going to run a tractor all day planting and harvesting a large field, we want to denote its strength in terms of sustained output in a biological analogue, not peak output.

Anonymous 0 Comments

A healthy adult human can generate around 1 hp peak, more or less.

(An Olympic athlete can produce over 3 hp at peak, but a couch potato might struggle at 0.5 hp).

Anonymous 0 Comments

The term horsepower is not referring to the peak energy output of a horse but rather the long time average output of a horse. If you were close to 750W on an exercise bike that was probably just for a short while. Similarly a horse can do 15 horsepower for a very short while. But just as you on the exercise bike the horse gets tired very quickly when doing that much work. If you were to take part in a long distance bike race such as the Tour de France there is no way you could do 750W, You might only do 200W average during the race. But you might only keep that up for 6 hours and have to rest until next day. So your total average would be down to 50W. This would be 1 humanpower.

Similarly if you have a horse pull a cart all day or power some machinery it can not do 15 horsepower all day. And after a few hours it would need rest. So its average over several days would be much closer to 1 horsepower. The unit was invented by the sales team of James Watt who were selling steam engines to replace horses at factories. They would measure the power output of the engines in horsepower. That meant that when they came to a factory to sell a steam engine they could simply just poke their head into the stables to see how big of an engine the factory needed. Unlike horses steam engines could output the same power all day and night without rest.