Cube Question In Space Geometry

  • Context: Undergrad 
  • Thread starter Thread starter xenogizmo
  • Start date Start date
  • Tags Tags
    Cube Geometry Space
Click For Summary
SUMMARY

The forum discussion centers on a space geometry question involving a cube and its shadow, specifically how the position of the sun affects the shadow's shape. The user, Xeno, concludes that the shadow can take the form of a hexagon and that for the shadow to be a square of 1 by 1, the sun must be perpendicular to one of the cube's faces. Additionally, Xeno notes that the diagonal of the cube's base, which measures x times the square root of 2, is relevant for determining when the shadow measures approximately 1.4.

PREREQUISITES
  • Understanding of basic geometric principles, including shadow formation.
  • Familiarity with cube properties and dimensions.
  • Knowledge of the relationship between light direction and shadow shape.
  • Basic trigonometry, particularly involving right angles and diagonals.
NEXT STEPS
  • Research the geometric properties of shadows in relation to light sources.
  • Explore the mathematical principles behind shadow projection in three-dimensional space.
  • Study the effects of different light angles on shadow shapes using geometric models.
  • Learn about the application of trigonometry in solving real-world shadow problems.
USEFUL FOR

Students of geometry, educators teaching spatial reasoning, and anyone interested in the mathematical relationships between light and shadow in three-dimensional objects.

xenogizmo
Messages
30
Reaction score
0
Hey everyone,
I came across this rather "uncoventional" space geometry question, from a dutch book. I have answers in mind but I want to check with you guys..
Check the attached picture for the cube..
The question goes like this:

This photograph of a cube was taken on a tropical island, so the sunbeams are directed almost perpendicular to the groud.

>In the pciture only part of the shadow is visible. What will the shadow look like "behind" the cube?

By changing the position of the cube or the sun, you can find different shapes of shadow. Assume the edge of the cube has length 1

>At which positions of sun and cube the shadow will be a square of 1 by 1?
>Describe a situation in which the shadow is a square with edges of length "root of 2" (approx. 1.4)

Now, I'll put my answers in the next post so that u can take your shot at the question first.

Thanks,
Xeno
 

Attachments

  • sample.cube.JPG
    sample.cube.JPG
    7.8 KB · Views: 526
Physics news on Phys.org
My Attempt..


Question 1: The shadow is a hexagon


Question 2: For the shadow to be 1x1, the sunbeams must be perpindular to one of the cube's faces

Question 3: The edge 1 was given for a reason I guess, (pardon me here, I'm not so familiar with the english terms) but I remember from back in school that if the edge length x then if we take a base of the cube, and draw a diagonal line from one edge to another, its length would be x by the root of 2 (I'm sure that line has a name, just don't know it)

So I guess the sunbeams must be perpindicular to one of hte edges of the cube, the one I marked with red in the picture attached to this post.

Tell if I'm right, and correct me if I'm wrong.
Thx
 

Attachments

  • sample.cube2.JPG
    sample.cube2.JPG
    9.5 KB · Views: 483
No ideas yet?? :rolleyes:
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
5K
Replies
3
Views
4K
  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K