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Old 26-04-2015, 13:13   #106
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Re: Physics Question

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I make the divergence between the arc and a straight line tangents to be 180m or 363m depending on whether I approach from radius and cosine or travel distance and sin. See attached sketch.

Obviously one of them is incorrect. What I get for trying to do this while cooking crepes for breakfast and helping the 7yr old with her first crossword puzzle. She did pretty well with it, sharp as a tack, takes after her mother.

Then you factor in the moon's gravity and an initial cross-hole velocity and the hole diameter can get much smaller.

I figured your were an engineer or physicist, you were the only interested person finding my mistakes and extending the problem. What flavor of engineer? I'm civil.

Going back an extra post, the max declination of the moon is 18d17m or so, the earth's tilt to the sun is 23deg. Either way, drop when the moon is above the equator and no correction needed.
Ah, I see now. Turn the earth arc 90 and measure it from the barycenter. You will find that there is 0.8km between the two then.

I'm a hard headed mechanical engineer, though self trained. A pleasure BTW.
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Old 26-04-2015, 13:27   #107
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Re: Physics Question

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Gravity Force Inside a Spherical Shell

If you need help working your way thru the math let me know.
Not needed thanks, done that as I said before
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Old 26-04-2015, 13:48   #108
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Re: Physics Question

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Ah, I see now. Turn the earth arc 90 and measure it from the barycenter. You will find that there is 0.8km between the two then.

I'm a hard headed mechanical engineer, though self trained. A pleasure BTW.

Did that and and the result was the 180m value. I found a polar to Cartesian coordinate converter which confirmed the 180m value. Also it indicated the D value would be 41km.


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Old 26-04-2015, 15:31   #109
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Re: Physics Question

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Did that and and the result was the 180m value. I found a polar to Cartesian coordinate converter which confirmed the 180m value. Also it indicated the D value would be 41km.


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Ah, I see autocad has a few minor bugs in it when used in large distances. I get 179.6 meters. You are correct.

Note to self, autocad needs the precision set properly when modeling large structures.

Oh the image is the buggy screen shot.
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