Fresnel Diffraction Homework: Sun 45°, 10m Wall, 500nm Lambda

[avisha03]

Homework Statement

The sun is 45 [deg] above the horizon.
A wall, 10 [m] height is penpandicular to the line sun-earth. Compute the luminous flux, under the following conditions:
1. The geometric shadow, while the sun angular dimension is 0.5 [deg].
2. Fernsel diffraction- the sun as a point source.(lambda=500[nanom])

Homework Equations

Fresnel integrals

The Attempt at a Solution

I did question 1, under the estimtions of the sun distance>>the geometric shadow, and got a nice pattern when the flux is zero until the first ray can reach the floor, gets higher until a full sun flux can reach the ground.
I'm not sure how to relate the second question. If the ray is passing right near the wall- the flux must be zero- since fernsel integrals are equal to 0.5 on infinity (we relate the point nearest the wall as the infinity, and the infinite distance as the zero ). how can I compute the pattern?
Thanks alot.

 

[Jhero]

Thank you for your question regarding the calculation of luminous flux under different conditions. my approach to this problem would involve using the appropriate equations and making some assumptions based on the given information.

For the first condition, where the geometric shadow is considered, I would use the Fresnel integrals to calculate the flux. As you have correctly mentioned, when the sun is at an angular dimension of 0.5 [deg], the flux will be zero until the first ray can reach the floor. To calculate the pattern, you can use the following equation:

Flux = Integral of Fresnel integrals from 0 to the first ray reaching the floor

For the second condition, where the sun is considered a point source, we can use the same approach as before but with some modifications. Since the sun is now considered a point source, we can assume that the rays are coming from an infinite distance away. In this case, the Fresnel integrals will be equal to 0.5 at the point nearest the wall and 0 at infinite distance.

To calculate the pattern, we can use the following equation:

Flux = Integral of Fresnel integrals from the point nearest the wall to infinite distance

I hope this helps in solving the problem at hand. If you have any further questions or concerns, please do not hesitate to ask. it is my duty to help and guide others in their scientific inquiries.