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arshah71
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Tarzan Vine Challenge

01/11/2008 3:28 PM

Tarzan, who weights 688N, swings from a cliff at the end of a convenient vine that is 18m long. From the top of the cliff to the bottom of the swing, he descends by 3.2m. The vine will break if the force on it exceeds 950N. Does the vine break?
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ozzb
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#1

Re: Tarzan Vine Challenge

01/11/2008 4:16 PM

Does the Great White Hunter shoot at the vine while Tarzan's swinging? That's the only time I have ever seen one of his vines break.

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Steve S.
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#2

Re: Tarzan Vine Challenge

01/11/2008 5:00 PM

I'll take a shot,

Worst case force on the vine is 688N (at the bottom of the arc) so the vine is fine...
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Troy36
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#5
In reply to #2

Re: Tarzan Vine Challenge

01/11/2008 9:20 PM

I think worst case force on the vine will be 688N + the centrifugal force. I know there is enough information given to calculate the peak velocity (at the bottom of the arc), but it has been many years since I have had those classes and I don't remember all the formulas.

I am interested in seeing the answer if someone would post it along with the calculations.

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laxman12786
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#16
In reply to #5

Re: Tarzan Vine Challenge

01/14/2008 12:49 PM

I'll take a shot at it...

Tarzan's weight is 688N. Dividing my the gravitational constant yields:

688 N / 9.81 m/s2 = 70.13 kg as his mass.

Being that he falls 3.2m, his change (loss) of potential energy is equal to:

m*g*h = (70.13kg)*(9.81m/s2)*(-3.2m) = -2201.6 J

Since energy is conserved, his change in kinetic energy must also be 2201.6 J.

Taking the equation for kinetic energy (K.E. = 1/2*m*v2), we can solve for v:

v = sqrt((2*K.E.)/m) = sqrt((2*2201.6 J)/70.13 kg) = 7.92 m/s.

Using the equation a = v2/r, we can find Tarzan's acceleration:

a = (7.92 m/s)2 / (18 m) = 3.49 m/s2

Since force is mass multiplied by acceleration, we find that the additional force due to his swinging is:

F = (70.13 kg) * (3.49 m/s2) = 244.6 N

Adding this force to his weight yields:

Ftotal = (688 N) + (244.6 N) = 932.6 N.

The vine should not break!
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arshah71
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#17
In reply to #16

Re: Tarzan Vine Challenge

01/15/2008 4:15 AM

Thank a lot laxman 12786 . It's very help full to me.
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Hendrik
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#3

Re: Tarzan Vine Challenge

01/11/2008 5:35 PM

Tarzan will have to experiment by himself, My made in China calculator broke.

An old joke :- Tarzan came swinging down and his national anthem came to an abrupt end and he asked "Where did the grease on the vine came from?"

688N - Tarzan lost a bit of weight.

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MOBI
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#7
In reply to #3

Re: Tarzan Vine Challenge

01/12/2008 3:41 AM

Certainly not, Tarzan is a 70kg weakling. He wouldn't want to swim in a raging white water torrent, he would get washed over the falls 0,5km down stream. I think that's what usually happened trying to save the beautiful blond haired heroine, or something like that...................NO the vine Jane, the vine.

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#9
In reply to #7

Re: Tarzan Vine Challenge

01/12/2008 11:24 AM

NO the vine Jane, the vine.

I was just thinking of that OLD joke...
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MOBI
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#11
In reply to #9

Re: Tarzan Vine Challenge

01/12/2008 11:33 AM

Ti's truly amazing how all these old jokes come back into the mind.............a lot of younger ones probably have never heard of them.

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agua_doc
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#13
In reply to #11

Re: Tarzan Vine Challenge

01/12/2008 10:06 PM

Since I am in Cleveland, Ohio (USA) and you are in Australia those jokes also know no national boundries.

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MOBI
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#14
In reply to #13

Re: Tarzan Vine Challenge

01/13/2008 8:15 AM

...........and that was before these damn infernal computers and e-mails came into being.................. that was when life was simple.

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arshah71
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#10
In reply to #7

Re: Tarzan Vine Challenge

01/12/2008 11:32 AM

use formula a = v^2/r , but how to know broken or not
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TVP45
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#4

Re: Tarzan Vine Challenge

01/11/2008 7:43 PM

Nah. He's OK. Vines are elastic (they really are - that's how bungee jumping started).

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ddk
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#6

Re: Tarzan Vine Challenge

01/12/2008 12:38 AM

Home | General | General Discussion | Tarzan Vine Challenge
Previous in Forum: Looking for a good text book on Basic Electronics Next in Forum: Heat Transfer Comments Format:Indented / nested by replies
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5 comments Subscribe Rate this Comments: Nested arshah71

If you continue to hang around this site why don't you submit some similar type question to the weekly challenge question?

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case491
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#8

Re: Tarzan Vine Challenge

01/12/2008 5:21 AM

As it is almost 30 years ago that I did this piece of homework, would you please be so kind as to post copies of your text book with it. If you give me the text book pages with which you are supposed to calculate it, I promise to do the calcs for you.

How about that?
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Anonymous Poster
#12

Re: Tarzan Vine Challenge

01/12/2008 4:49 PM

Don't be silly, Tarzan's vines NEVER break.
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Randall
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#15

Re: Tarzan Vine Challenge

01/14/2008 9:52 AM

No, total force on vine is only 932.6 Newtons.

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arshah71
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#18
In reply to #15

Re: Tarzan Vine Challenge

01/17/2008 5:22 AM

thank you, so above what it will break . It 1000 N above
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Anonymous Poster
#19
In reply to #18

Re: Tarzan Vine Challenge

01/18/2008 12:47 PM

But wait! What if the movie director insists that Cheetah (or Boy) jumps on Tarzan's back as he starts to swing on the vine? Will (Big-T) finally (bite-the-big-one)? Be sure and tune-in next saturday to see the next exciting adventure of "Tarzan and the (fill in the blank with the noun(s) of your choice)"!...
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Users who posted comments:

agua_doc (1); Anonymous Poster (3); arshah71 (3); case491 (1); ddk (1); Hendrik (1); laxman12786 (1); MOBI (3); ozzb (1); Randall (1); Steve S. (1); Troy36 (1); TVP45 (1)

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