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Anonymous
>>189128
Ripped from howstuffworks.com
* 1 horsepower is equivalent to 746 watts. So if you took a 1-horsepower horse and put it on a treadmill, it could operate a generator producing a continuous 746 watts. * 1 horsepower (over the course of an hour) is equivalent to 2,545 BTU (British thermal units). If you took that 746 watts and ran it through an electric heater for an hour, it would produce 2,545 BTU (where a BTU is the amount of energy needed to raise the temperature of 1 pound of water 1 degree F). * One BTU is equal to 1,055 joules, or 252 gram-calories or 0.252 food Calories. Presumably, a horse producing 1 horsepower would burn 641 Calories in one hour if it were 100-percent efficient.
So 1hp = 641 calories per hour @ 100% efficiency.
Humans are about 22% efficient according to various studies. Let's be generous and say 25% for simplicity.
So, for a human being to output 1hp over the course of an hour it would require 2564 calories of energy. Since 1hp = 746 watts, then 300w of output is 0.4 hp.
Hence, 1 hour @ 300w (0.4hp) is 1031 calories/hr.
That's assuming 25% efficiency. Over time, that efficiency will go down. So the estimate used by some of the ellipticals isn't that far off.
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