lgbasallote
In 1990, walter arfeuille of belgium lifted a 281.5 kg object through a distance of 17.1 cm using only his teeth
(a) how much work was done on the object by arfeuille in this lift, assuming the object was lifted at constant speed?
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lgbasallote
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im thinking \[-\Delta U_{GRAV}?\]
rajathsbhat
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Right-o!
lgbasallote
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so \[\implies -(281.5)(9.8)(0-0.171)?\]
i change this to meters right?
rajathsbhat
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0.171 is in metres already. I don't get your question.
rajathsbhat
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that multiplication is the answer though..
lgbasallote
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the given was 17.1
i was confirming that i needed to change that to meters
lgbasallote
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or do i use 17.1?
rajathsbhat
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ah, yes, it is 0.171 that you need you need to use.
lgbasallote
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ahh thanks
CarlosGP
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His work was used to increase potential energy of the weight, therefore you can calculate like W=mgh=281.5x9.81x0.171 J
I have heard that the work done later on by his dentist to fix his dentures was quite hard
lgbasallote
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a follow up question was
(b) What total force was exerted on arfeuille's teeth during the lift
what does that mean?
CarlosGP
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The forced exerted was exactly F=mg=281.5 x 9.81 Newtons
rajathsbhat
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It means that a downward force equal to the weight he lifted will be exerted on his teeth (the contact point).
rajathsbhat
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Btw, @CarlosGP, I saw a man on TV lift a 1000kgs (a ton) with his teeth. Jus sayin.
CarlosGP
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I saw another one make the Statue of Liberty disappear! ;) Can you believe it?
rajathsbhat
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but this was for real. It was on 'Superhuman' on the DISCOVERY CHANNEL!
CarlosGP
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I have to see under which conditions was the test carried out. I am not too sure neck muscles can stand that force
rajathsbhat
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I'll try to find a video..
CarlosGP
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@rajathsbhat, I would appreciate it! Thanks!
lgbasallote
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so for (b) it's just gravitational force?
lgbasallote
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@rajathsbhat
rajathsbhat
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yes. Sorry, I was busy searching for that vid.
lgbasallote
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haha lol...
rajathsbhat
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and yes, it is the gravitational force.
lgbasallote
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thanks!!`
rajathsbhat
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yw.