Human power

[gar]

150205-1049 EST

As a normal adult individual can you alone ---

Raise a 16,500 pound object 1 foot in 1 minute?

Raise a 33,000 pound object 1 foot in 1 minute?

What peak power do you believe you can produce with your legs running up a flight of stairs? How can you perform this experiment?

.

 

[Besoeker]

150205-1049 EST

As a normal adult individual can you alone ---

Raise a 16,500 pound object 1 foot in 1 minute?

Raise a 33,000 pound object 1 foot in 1 minute?

What peak power do you believe you can produce with your legs running up a flight of stairs? How can you perform this experiment?

The answer to the first two questions is no for most adults.
From school physics I remember being told that about a tenth of a horsepower was about what a reasonably fit person could achieve. A trained athlete like the rowers in that famous boat race (Oxford/Cambridge) and competition cyclists can achieve more of a short period.

How would you measure the stairs thing?
Weigh yourself, measure the height of the stairs and have a stopwatch at the ready.
And calculate foot pounds per minute once you get your breath back!

 

[petersonra]

The answer to the first two questions is no for most adults.
From school physics I remember being told that about a tenth of a horsepower was about what a reasonably fit person could achieve. A trained athlete like the rowers in that famous boat race (Oxford/Cambridge) and competition cyclists can achieve more of a short period.

How would you measure the stairs thing?
Weigh yourself, measure the height of the stairs and have a stopwatch at the ready.
And calculate foot pounds per minute once you get your breath back!

I have heard 50W is about what a person in average shape can sustain, and about 100W for a trained athlete.

 

[ggunn]

150205-1049 EST

As a normal adult individual can you alone ---

Raise a 16,500 pound object 1 foot in 1 minute?

That would be the same as raising 100 165 lb objects 1 foot in 1 minute. I don't think I could do it (I know I couldn't) but I guess it's possible that there are athletes who might be able to.

A 1000:1 chain hoist would only have 16.5 lbs resistance (assuming no losses), but I'd have to pull 1000' of chain through it. I don't think so.

 

[Besoeker]

That would be the same as raising 100 165 lb objects 1 foot in 1 minute. I don't think I could do it (I know I couldn't) but I guess it's possible that there are athletes who might be able to.

A 1000:1 chain hoist would only have 16.5 lbs resistance (assuming no losses), but I'd have to pull 1000' of chain through it. I don't think so.

The figures Gar gave are for 0.5HP and 1HP respectively.
Beyond the capability of normal adults.

 

[ggunn]

The figures Gar gave are for 0.5HP and 1HP respectively.
Beyond the capability of normal adults.

I'm glad to hear that I am normal in that respect, anyway.

 

[K8MHZ]

The physical therapy dept at our hospital had a stationary bike that displayed your output in watts.

I could peak at about 1 hp (750 watts) and could hold 100 watts for a minute or two. Once you get tired, your output drops like a rock.

 

[K8MHZ]

From answers.com

The question was how much hp can a man on a bike produce. Since the bike doesn't add any hp, I think it's safe to apply the answer to just the man.

Depends on the time span. Strong sprinters can put out nearly 2 Hp for short bursts, but for sustained effort it's way lower, around 0.5Hp.

 

[gar]

150205-1243 EDT

Peak short time, one second range, power that a fit adult male can produce is in the 3/4 to 1 HP range. Last time I checked my use of one arm on a crank generator at the Henry Ford Museum was about 3/4 HP. I had a visitor there once that hit about 1.1 HP. It takes more than 1 second to get the generator up to speed, but you can not sustain that power level long.

We ran the stair test in High School physics and my memory is that about 3/4 HP was typical. This was longer than one second.

Sustained average power output is considerably below peak capability.

From an electrical perspective it is interesting to make this human comparison.

.

 

[under8ed]

150205-1049 EST

What peak power do you believe you can produce with your legs running up a flight of stairs? How can you perform this experiment?

.

I heard about this race for the first time this morning, at the Empire State Building.
The course record is 9 minutes and 33 seconds for men to run up the 86 floors of steps.
1576 steps to be exact.

http://news.yahoo.com/racers-step-annual-empire-state-building-climb-050533207.html

 

[K8MHZ]

150205-1243 EDT

Peak short time, one second range, power that a fit adult male can produce is in the 3/4 to 1 HP range. Last time I checked my use of one arm on a crank generator at the Henry Ford Museum was about 3/4 HP. I had a visitor there once that hit about 1.1 HP. It takes more than 1 second to get the generator up to speed, but you can not sustain that power level long.

We ran the stair test in High School physics and my memory is that about 3/4 HP was typical. This was longer than one second.

Sustained average power output is considerably below peak capability.

From an electrical perspective it is interesting to make this human comparison.

.

Very interesting.

Especially with the interest of alternate emergency power needs. The only dependable means to charge batteries is by human power. Having some knowledge about available human output would be handy when figuring out how much charge a human powered generator could put into a battery.

I could do 70 - 100 watts for 5 minutes. Knowing that, even with a 100 percent efficient generator, makes me realize that my effort for five minutes is only good for .5kWh. That equates to putting a 2 amp charge into a 12 volt battery for 20 minutes with no conversion losses on my best day.

 

[Besoeker]

150205-1243 EDT

Peak short time, one second range, power that a fit adult male can produce is in the 3/4 to 1 HP range. Last time I checked my use of one arm on a crank generator at the Henry Ford Museum was about 3/4 HP. I had a visitor there once that hit about 1.1 HP. It takes more than 1 second to get the generator up to speed, but you can not sustain that power level long.

We ran the stair test in High School physics and my memory is that about 3/4 HP was typical. This was longer than one second.

Sustained average power output is considerably below peak capability.

From an electrical perspective it is interesting to make this human comparison.

.

Shows how puny we are.

 

[gar]

150105-1659 EST

A rough calculation of average HP, based on a weight assumption.

Assume a 150 # man. The 86th floor is at a height of 320 meters or 1050 ft. To raise 150 # to the 86 th floor takes 150*1050 = 157,500 ft-# of work. If done in 1 minute this requires 157,500/33,000 average HP = 4.77 HP. Thus, if done in 9.5 minutes the average HP required is about 4.77/9.5 = 0.50 average HP.

This could not be sustained for long periods.

.

 

[gar]

150206-0940 EST

Suppose you could maintain 0.5 HP output for 1 hour, which you can not, then your energy ouput would be 746/(2*1000) = 0.373 kWh, and at my electric cost my payment for this energy would be 0.373*0.16 = $ 0.06 . Not a profitable enterprise to generate your electricity by this method.

.

 

[kwired]

150206-0940 EST

Suppose you could maintain 0.5 HP output for 1 hour, which you can not, then your energy ouput would be 746/(2*1000) = 0.373 kWh, and at my electric cost my payment for this energy would be 0.373*0.16 = $ 0.06 . Not a profitable enterprise to generate your electricity by this method.

.

Depends on cost of fuel (food).

Back to last question in OP - how can you perform this experiment? How about huge squirrel cage with the person being a huge lab rat running inside and have the squirrel cage drive a generator - then measure generator output

 

[K8MHZ]

150206-0940 EST

Suppose you could maintain 0.5 HP output for 1 hour, which you can not, then your energy ouput would be 746/(2*1000) = 0.373 kWh, and at my electric cost my payment for this energy would be 0.373*0.16 = $ 0.06 . Not a profitable enterprise to generate your electricity by this method.

.

I don't think the intent is to compete with available power. I think the intent is to determine how much output one could expect should all that be available is human power.

There are a number of pedal powered generators on the Internet. There are videos about using cordless drills as small generators to charge small batteries.

 

[kwired]

I don't think the intent is to compete with available power. I think the intent is to determine how much output one could expect should all that be available is human power.

There are a number of pedal powered generators on the Internet. There are videos about using cordless drills as small generators to charge small batteries.

There are also "crank to charge" flashlights.

 

[K8MHZ]

Depends on cost of fuel (food).

Back to last question in OP - how can you perform this experiment? How about huge squirrel cage with the person being a huge lab rat running inside and have the squirrel cage drive a generator - then measure generator output

Here is one way, buy an exercise bike from Kettler.

Informative computer provides the following work out data: Speed, RPM, Distance, Time, Energy Consumption, Pulse Rate, and Performance in Watts

www.kettlerusa.com

 

[K8MHZ]

There are also "crank to charge" flashlights.

I have a couple of those.

Light is easy to make. I am thinking more along the lines of charging batteries for communications. There are basically two standard voltages to deal with. 1.5 volts for hand held FRS type radios, and 12 volts for mobile and fixed stations (base stations to the layperson).

The small radios typically use 4 batteries for a 6 volt system. In a pinch, a 12 volt generator could be used to charge 8 AA cells in series.

If 120 VAC is needed, inverters are everywhere.

 

[gadfly56]

150206-0940 EST

Suppose you could maintain 0.5 HP output for 1 hour, which you can not, then your energy ouput would be 746/(2*1000) = 0.373 kWh, and at my electric cost my payment for this energy would be 0.373*0.16 = $ 0.06 . Not a profitable enterprise to generate your electricity by this method.

.

Based on caloric intake, humans are the equivalent of a 120W power source. This of course includes whatever is required to simply keep the "engine" going and is otherwise not available for useful (however defined) work. If we assume that 100W is available, then in the course of an 8 hour day, a human being can do 800 W-hr of useful work. So back in the day, if you kept a few slaves, this is what you might, more or less, get from them. Let's have them work 16 hr/day and make it 1.6 kW-hr per head. My family of 4 consumes, roundly, 1,000 kW-hr/month, or about 33 kW-hr/day. This would be similar to having 21 slaves at our beck and call. This is an illustration of how liberating access to cheap electrical power has been to those of us lucky enough to have been born into a 1st world country. Obama and Co. have put the kibosh on funding in 3rd world countries for cheap coal-fired power plants. If you want a prime example of colonial-style repression, you couldn't find better.