arc length

The rope could be in the shape of a semi-circle. If you want to assume that it is in such a form, take a measurement of the distance between the top of one of the poles and the lowest point on the rope, this will be your radius. Now, use the circumference formula for a semi circle (pi*radius) to find he length of your rope. Simple

[edited by - h0-0t on April 12, 2003 3:56:16 PM]

I guess I asked my question wrongly then...I need to find the distance between the two poles, not the length of the arc.

Hi,

I approximate the length between the poles to be 100 feet.

/Mankind gave birth to God.

[edited by - silvren on April 12, 2003 5:14:32 PM]

quote:

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Original post by GravtyKlz
I guess I asked my question wrongly then...I need to find the distance between the two poles, not the length of the arc.

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Well, you''ve got a 150ft long catenery (hyperbola)

so y = Acosh(Bx) + C

x = 0 is halfway between the poles. A,B and C are constants - finding their values is the exercise. Then you will know at what values of x you have y = 100ft.

The shape of any thin cable hanging in a uniform gravitational field will take the form of a catenary, y=cosh(x)=(e^x+e^-x)/2. To find the distance between the poles, you need to analyze the curve itself. You know the arclength, and three points that the curve passes through. With these values, (actually, you only need two points and the arclength) you can find the unique catenary curve. If you haven''t taken physics and calculus, you probably won''t be able to understand the derivation, but the equation is fairly simple, if you set up your coordinate system correctly. I don''t know it offhand, and I don''t know the derivation, so that''s all the help I can offer. If you need only approximate values, you can use a graphing calculator to figure them out.

quote:

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Original post by GravtyKlz
This isnt a school question either.

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Well, okay, but it sounds like a homework problem. And not that I don''t trust you, but when you ask a question that sounds like you''re asking a homework question, please in the future show us YOUR work, .



Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.

This problem is too similar to another post, and both are very homework-like without following the forum rules for homework type problems. Therefore, I''m closing the thread.

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Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.