I'm pretty sure that this question isn't as hard as I'm making it, but I'm having a brain block here.(adsbygoogle = window.adsbygoogle || []).push({});

Tarzan, who weighs 700 N, swings from a cliff at the end of a convenient vine that is 17 m long. From the top of the cliff to the bottom of the swing, he descends by 5.3 m. The vine will break if the force on it exceeds 1580 N. What would the greatest force on the vine be during the swing?

I'll show you guys how far I've gotton and then maybe you can help me from there, or show me where I am mistaken

Emech(initial) = Ep + Ek

Emech(initial) = mgh

Emech(initial) = 700*5.3

Emech(initial) = 3710

Emech(final) = Ep + Ek

Emech(final) = Es + Ek

Emech(final) = (kx^2)/2 + (mv^2)/2

*We can assume Emech is conserved

3710 = (kx^2)/2 + (mv^2)/2

kx^2 + mv^2 - 7420 = 0

Also I know that

F= m*a

F=mv^2 / R

And,

kx^2 + mv^2 - 7420 = 0

v^2 = (7420 -kx^2) / m

F = 7420-kx^2 / R

F = 7420-kx^2 / 17

Also,

Fmax = kx

1580 = kx

1580/x = k

Sub intoF = 7420-kx^2 / 17

F = (7420 - 1580x) / 12

And thusly I am stuck.

Too many unknowns, not enough equations.

:surprised

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# Homework Help: Tarzan! King of the Jungle

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