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Effortless actions of a human being

  1. May 11, 2015 #1
    Hey guys, the question for this thread is, how can I find out what the heaviest object an average human can move effortlessly is? and by that I mean literally effortless to the point where it requires little to no force, even less than easy to move an object.

    One example I could give is picking a sock out of sock draw, but that is not necessarily the heaviest object that a human can move effortlessly. I am sure there is a way of finding this out based on a humans body, mass and what not.

    Estimates will do, something and theoretical as this is unlikely to give us a 100% accurate result.

    Or is it impossible? thanks guys for any help.
     
  2. jcsd
  3. May 11, 2015 #2

    phinds

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    I think your "effortlessly" is totally subjective and has no concrete answer. All movement, including just moving your arm, involves effort. What different people define as "effortlessly" using your definition will not be the same for them when they are 80 as it was when they were 20 and a weightlifter would like think of a few pounds as meaningless whereas a frail woman might not find it "effortless" at all.
     
  4. May 11, 2015 #3
    So what if I made the example a bit more concrete? Lets use a strong man as our example;



    Houston Alexander, 3 minutes in.

    We have some examples of producing forces, so is there no way to know what would be effortless for such a man? not necessarily from his point of view but physically, as in, a man who can output that much force with a strong 600 pounds punch, how much force would he hit with if he hardly tried? As in, the very least effort he could put in.

    Perhaps its possible to calculate from force required just to move his arm? As humans do that without even thinking?
     
  5. May 11, 2015 #4

    phinds

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    I think you're chasing opinion here, not fact. What's your point in all this?
     
  6. May 11, 2015 #5
    I want to find the difference between someone actively using a lot of force and the same person using "effortless" actions or little to no effort.
     
  7. May 11, 2015 #6

    DaveC426913

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    I have to agree with phinds. The moment you try to quantify it, you will find that the energy output is directly proportional to effort. There's no case where something can be done that doesn't require a commensurate amount of effort. i.e. TANSTAAFL (There ain't no such thing as a free lunch.)

    Frankly, it probably takes more effort per unit work done for small amounts of work than it does for larger amounts, though I can't be sure of this. Think of a car engine. It is not very inefficient at low speeds (and high speeds). It is most efficient at middling speeds.

    I think what you're really doing is quantifying a subjective human "qualia" - i.e. at what point does a human (whose body is always doing a million things - enough to generate a heat output equivalent to a 60-watt lightbulb) think a given action (such as lifting an object or punching someone) to be a 'signal' so minor as to be lost in the 'noise' of normal metabolism.
     
    Last edited: May 11, 2015
  8. May 11, 2015 #7
    Thank you for your aid guys, so it would seem there is no possible way to determine it. To determine what is as you say;

     
  9. May 11, 2015 #8

    DaveC426913

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    It's not so much that it can't be done, it's that it's subjective. Which is kind of like saying 'there is no wrong answer'.

    Which is why phinds is asking you what the application is. This will give us clues as to what criteria are more important in the determination of effort.
     
  10. May 11, 2015 #9
    I guess I want to know what effortless means in terms of a human like Houston in my video, I then want to know the difference in force the body excerted to do his first punch which came out at 600 pounds of force and how much force is in the effortless activity. Then I want to apply that difference to this;



    12 minutes and 30 seconds in, you can see this character effortlessly moves that cube as stated by the narrator. Now upon making a few assumptions myself and my associates can put together figures for the force required to move a block like that, and impale claws into it.

    However, we want to know how much force he can put in a strike if he was actually exerting effort, that way we could at the very least estimate how hard hes hitting this guy in the video;



    2 minutes 15 in.


    So the goal is to find out eventually how much force the character getting hit is being struck with. If the character can without effort move what has been estimated as blocks that must weigh in the tons, then how much can he output when enraged and actually trying to harm someone?


    PS.

    How do you show videos from a certain time? I try and use youtubes own "copy url at time" option but that did not work, neither did another site that linked the timings for me. But this site seems to remove timings.
     
  11. May 11, 2015 #10

    DaveC426913

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    This is fantasy. And computer-programmed at that. The actions available are whatever meets the needs of the story-line. There's no physics here, and no biology.

    I feel like you've pulled a bait and switch on us.
     
    Last edited: May 11, 2015
  12. May 11, 2015 #11

    Ryan_m_b

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    Firstly there is literally no thing as effortlessly. All lifting requires energy so that's a nonstarter from there. In terms of feeling effortless that basically comes down to feelings of comfort and pain which are notoriously subjective. There's been a tonne of research into how to assess levels of pain in patients and the gold standard is still just asking them to rate it on a scale of 1 to 10. That's the closest you're going to get to an answer, if you created a questionnaire and asked a large group of people questions like:

    "For the following activities please indicate the level of effort you feel you exert on a scale of one to ten (one being effortless and ten being the limit of your capability)"

    1) Lifting a sock from a waist height draw
    2) Lifting a sock from the ground
    3) Lifting an apple from a table to your mouth
    4) Lifting an average bag of shopping
    ......"

    That taken with data like age, health concerns, occupation etc would give you some data on what would be effortless for different demographics.

    EDIT: With regards to your videos those are video game characters, the physics behind their movements are inconsistent and made up. The inconsistency is key: it the game dev wants you to be able to move a block then the character will move one. They will generally not work backwards to calculate how strong that makes the character and make the rest of the movements scale to that. The character's strengths and capabilities will be whatever they need to be to tell the story.
     
  13. May 11, 2015 #12
    I see, so effortlessness is not factually quantifiable as a general formula or rule? If someone feels its easy then its effortless for them but feeling and what not can be questioned as well. Hm, well you guys have given me some ideas to be getting on with, thank you.
     
  14. May 11, 2015 #13

    Ryan_m_b

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    No, there's very little general formulas or rules in psychology.
     
  15. May 11, 2015 #14

    Drakkith

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    No such concept exists. Force, in physics, is an interaction that accelerates a mass. There is literally no way to move an object without exerting a force on it. The quicker you accelerate it, the more force is applied.
     
  16. May 11, 2015 #15

    DaveC426913

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    Yes, well... if this thread were moved to a more appropriate forum, I'd agree. But it bull-headedly remains in the "Squishy Science" forum, to my chagrin... :mad:
     
  17. May 11, 2015 #16

    Ryan_m_b

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    The thread related to conscious perception and biomechanics. It is in the right forum.
     
  18. May 13, 2015 #17

    jedishrfu

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