Sun path

H

Harroman

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Feb 20, 2017
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I have a large stone 12 feet tall and there is a 1 foot hole drilled in it at an angle. As the sun moves across the sky how long does it take to move from one edge of the hole to the other.
 
What do you mean by "move from one edge of the hole to the other"? The sun is, of course, not in the hole so you cannot mean that literally.
 
Sorry for not being more clear. If you were looking up through the hole and the sun passed across the hole how long would it take.
 
The circular opening at the far end of the hole is one foot wide. How far away from your eye is the opening at the far end of the hole?

This distance determines the field of vision.

Think of a circular opening in a sheet of paper. If you hold the opening directly in front of your eye, you can almost see the entire width of the room. As you move the paper farther away from your eye, the width of the room visible through the opening becomes narrower. The distance from your eye determines the field of vision.
 
Trying again to define the question.
I have a large stone which is part of an art installation consisting of 11 stones in a circle - loos like a small Stonehenge.
The stone I am talking about is 12 feet high and 5 feet thick and facing south. A hole of diameter 1 foot is to be drilled through it at an angle.
As the sun rises through the day it will start to shine on the stone and create a shadow. As midday approaches the sun will start to shine down the hole to create a pool of light in the shadow. It will then move across the hole and eventually stop shining through the hole. What I need to know is how long it will shine through the whole.
 
Harroman said:
Trying again to define the question.
I have a large stone which is part of an art installation consisting of 11 stones in a circle - loos like a small Stonehenge.
The stone I am talking about is 12 feet high and 5 feet thick and facing south. A hole of diameter 1 foot is to be drilled through it at an angle.
As the sun rises through the day it will start to shine on the stone and create a shadow. As midday approaches the sun will start to shine down the hole to create a pool of light in the shadow. It will then move across the hole and eventually stop shining through the hole. What I need to know is how long it will shine through the whole.
Click to expand...
Is this question part of a school project?
 
No.
As there are no answers it looks like it might be too hard a problem for this group. Does anyone know of a better site who might help?
 
Harroman said:
No.
As there are no answers it looks like it might be too hard a problem for this group. Does anyone know of a better site who might help?
Click to expand...
The reason there have been no answers (aside from the fact that this is a tutoring site, not a "cheetz" site) is the same reason that there have been so many requests for clarification. You want a precise mathematical answer to a vague physics question. Lacking precise inputs, we cannot proceed.

If you are needing a contractor to do design work for you, you might want to consider hiring a qualified local professional, as "ideal" mathematical answers would almost certainly not be what you're wanting. If you're wanting to learn the math, then please first re-read the "Read Before Posting" announcement for this forum, and then reply with the complete specs for this exercise, along with a clear listing of your thoughts and efforts so far. Once we finally have enough information (including what you've tried and where you're stuck), we can begin to work with you.

Thank you! ;)
 
If the centre of the hole is 11 feet from the ground then a semi
circle starting at the ground and passing through the circle and
back to the ground would have a length of pi * 11 (ie half the
circumference) which is 34.557 ft. Of this length the hole is
therefore 1/34.557 part of it.
I then assumed that on a certain day (in the UK) the sun takes 12
hours or 720 minutes to rise and then set. Obviously varies, but
if my thinking is correct for this example then I can re-
calculate.
Therefore the time spent passing the hole is (1/34.557) * 720 =
20.83 minutes.
These are my thoughts, but I have no idea whether they are correct
or not.
Any help would be gratefully received.
 
Harroman said:
If the centre of the hole is 11 feet from the ground then a semi circle starting at the ground and passing through the circle and back to the ground would have a length of pi * 11 (ie half the circumference) which is 34.557 ft. Of this length the hole is
therefore 1/34.557 part of it.
I then assumed that on a certain day (in the UK) the sun takes 12 hours or 720 minutes to rise and then set. Obviously varies, but if my thinking is correct for this example then I can re-calculate.
Therefore the time spent passing the hole is (1/34.557) * 720 = 20.83 minutes.
These are my thoughts, but I have no idea whether they are correct or not.
Any help would be gratefully received.
Click to expand...
Okay, but we still need all of the parameters. You mentioned an "angle" at one point. What is that angle? With respect to what? What is the thickness of the material through which the hole is drilled? Where in your computations do you take account of the angle of the sun with respect to aspect of the drilled hole?

You're insisting that we should be able to give you an answer accurate to two decimal places, but this is simply impossible without specific inputs. Please provide that information.
 
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