Mystery Cache

Owl Hunt

A cache by .jpeg Send Message to Owner Message this owner
Hidden : 1/10/2012
In Texas, United States
3 out of 5
1 out of 5

Size: Size: not chosen (not chosen)

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Geocache Description:

This puzzle was constructed by our son, a recent graduate of another university west of here. Enjoy!

Owl hunt
A convex mirror and a concave mirror are placed on the same optic axis, separated by a distance L=0.6m.  The radius of curvature of each mirror has a magnitude of 0.36m.  A light source is located a distance x from the concave mirror (as shown in figure).  What distance x will result in the rays from the source returning to the source after reflecting first from the convex mirror and then from the concave mirror?  Answer: A.BC m
We know a specific camera lens has a focal length of 180mm and an aperture diameter of 16.36mm.  If the correct shutter speed of a certain scene with these values is 1/30s, what would the equivalent exposure be at f/2.8? Answer: B.ADE ms
A 35mm camera has a standard lens with focal length 50mm and can focus on objects between 45cm and infinity.  Cameras focus by rotating the lens, therefore increasing or decreasing the lens's distance from the film (or sensor).  What is the upper bound of the range of distances between the lens and the film to focus properly over the 45cm to infinity range? Answer: FG mm
N 29° CE.BDC W 095° BC.AGD

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Current Time:
Last Updated: on 12/27/2016 8:49:43 AM (UTC-08:00) Pacific Time (US & Canada) (4:49 PM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum