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Why can't I lift myself up

why can't I lift myself up using my own arms, like how you could carry a baby

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I don't think it's a pointless question at all! Why, if your arms can exert a force upwards, can't you lift yourself up? Of course, you can if you have a beam and pulley and throw a rope over the pulley and pull on it - up you go.

So, why doesn't that work if you push down? JeffM has it right - it's Newton's Law - every action has an equal and opposite reaction. In the case of the beam, the ends of the beam have an upward force applied by the wall that holds it. In the case of you just lifting yourself up, what are you pushing against? Where's the reaction?
If you lift a baby up, the extra weight is transmitted through your feet and you weigh more - no surprise, you are now holding a fat, bawling infant. The increased weight is balanced by a balancing upward force from the floor. That force is what you don't have if you grab yourself by the scruff of the neck and yank up - your head may come off, but your feet will remain firmly planted and blissfully unaware of the suicidal machinations a few feet up...

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Hmmm...reading too much Dozy these days?
I HATE it when my feet become aware of my suicidal machinations...
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Somehow I think only Muldoon would be able to rip his own head off by firmly grasping the scruff. Dozy?
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Thank heaven we have Ask as a forum to contemplate these important scientific potentialities...not to mention our contribution to the terraforming of Venus...
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We cannot lift ourselves simply because of the Newton's 3rd Law of motion. It states that "forces always occur in pairs. If an object "O" exerts a force "F" on object "A", then object "A" exerts an equal and opposite force "F" on object "O". So if you try to lift yourself, the force of gravity pulls you down using the same force you are using.

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Wow
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Nerd... Nah just jokin but that was a very intelligent answer
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Lmao ^
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Wools I meant ^^
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Is there anything Jeff, doesn't know?
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Jeff has never asked a question??!
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Gravity it has to do with it.

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Lots of fine, erudite answers here, and I cringe at the thought of contradicting these wonderful people, but I believe it has to do with physical strength and the fact that your name is not Muldoon.

According to Robert Heinlein Muldoon was so strong that he could put his hand in his own hip pocket and hold himself out at arm's length.

Don't try this at home. It's Muldoon I'm talking about.

I suspect that Heinlein pinched the idea from the old Bing Crosby song, "Two Shillelagh O'Sullivan."

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Oh I was hoping you would weigh in on this question with Muldoon!
Now got to go and green up Waldorff...he is definitely saying something similar - with erudition!

And someday I AM going to try it myself at home!
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Don't try this at home? Ok, I read this and I AM trying it at home.

So far, it's not working. I'll hit the barbells tomorrow and try again...

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You might have to opt for a name change, first. Muldoon!!!
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