Re: missile lauch

Message posted by lone wolf on December 02, 2003 at 19:58:34 PST:

Using the angel created by looking at the top of bald mountain from rachel, the rocket would have to be about 115k ft high to be seen from Rachel. [The visual horizon calculation assumes no mountains in the way.] I find 115k ft hard to believe, so I hope you will check my math.

You can check this a couple of ways. First you need a few physical dimensions. The distance from Rachel to Vandenberg is 333 miles. Bald Mountain elevation is 9469ft, while Rachel (according to the not so good Garmin mapsource) is at 4774ft, yielding an elevaton change of 4695ft. [Spock would include the height of the person doing the observation.] The distance from Rachel to Bald Mountain is 13.5 miles. When the dust settles, this makes an angle of about 3.77 degrees. [The math of course must be done in radians, but it is good to have the angle in degrees to help visualize the problem.] Now you could multiple the tanget of 3.77 degree times the distance in ft from Rachel to Vandenberg to get the height of the rocket. You could also just use the angle in radians and take the small angle approximation. Lastly, you could use properties of similar triangles, where the first triangle is that from Rachel to Bald Mountain, and the second goes from Rachel to Vandenberg, which ends up having a scale factor of 24.67. You multiply 24.67 times the height difference between Bald Mountain and Rachel to get roughly the same 115k ft.

In Reply to: Re: missile lauch posted by Chuck Clark on December 02, 2003 at 13:17:02 PST:


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