Custom Solid with Elliptical Cross Sections Parallel to yAxis

Custom Solid with Elliptical Cross Sections Parallel to yAxis
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2019-04-07 10:18
This example demonstrates a solid where the cross sections parallel to the yAxis are ellipses, with the minor axis lying in the base. By adjusting the eccentricity of the cross-sectional ellipse, the shape of the sections can be observed to change. The construction uses commands such as Segment, Intersect, Line, Textfield, Sphere, CurveCartesian, Point, Conic, Eccentricity, and Surface in GeoGebra. Suitable for calculus education to help students understand the concept of cross sections in solid geometry.

GeoGebra Commands & Parameters

  1. Segment(H, I) → s_1
  2. Midpoint(s_1) → A_1
  3. Segment(J, K) → q_1
  4. Midpoint(q_1) → Z
  5. Midpoint(s_1) → E
  6. Midpoint(q_1) → F
  7. Intersect(upper, h, (0, 6)) → B
  8. Intersect(lower, h, (0, -7)) → C
  9. Segment(C, B) → q
  10. Intersect(upper, q, (0, 6)) → G
  11. Midpoint(C, G) → T
  12. Line(B, D) → i
  13. Segment(C, B) → p
  14. Textfield(upper) → InputBox1
  15. Textfield(lower) → InputBox2
  16. Textfield(a) → InputBox3
  17. Textfield(b) → InputBox4
  18. Segment(C, G) → k_1
  19. Line(C, G) → j
  20. Line(T, T + (1, 0, 0)) → m
  21. Line(F_1, F_1 + (1, 0, 0)) → n
  22. Line(Z, Z + (1, 0, 0)) → f
  23. Line(D_1, D_1 + (1, 0, 0)) → g
  24. Line(T, T + (0, 0, 1)) → l
  25. Sphere(T, Distance[G, T] / sqrt(1 - ecc^(2))) → c
  26. Intersect(l, c) → V, W
  27. CurveCartesian(x(C), y(T) + ((y(G) - y(T)) * cos(t)), ((z(W) - z(T)) * sin(t)), t, 0, (2 * pi)) → e
  28. Point(e) → E_1
  29. Line(E, E + (0, 0, 1)) → r
  30. Point(e) → G_1
  31. Conic(W, G_1, C, V, G) → s
  32. Eccentricity(s) → k
  33. Sphere(A_1, Distance[H, A_1] / sqrt(1 - ecc^(2))) → o
  34. Intersect(r, o) → J_1, K_1
  35. CurveCartesian(x(A_1), y(A_1) + ((y(H) - y(A_1)) * cos(t)), ((z(K_1) - z(A_1)) * sin(t)), t, 0, (2 * pi)) → t
  36. Point(t) → L_1
  37. Conic(K_1, L_1, I, J_1, H) → c_1
  38. Line(F, F + (0, 0, 1)) → f_1
  39. Sphere(F, Distance[J, F] / sqrt(1 - ecc^(2))) → u
  40. Intersect(f_1, u) → M_1, N_1
  41. CurveCartesian(x(F), y(F) + ((y(J) - y(F)) * cos(t)), ((z(N_1) - z(F)) * sin(t)), t, 0, (2 * pi)) → v
  42. Point(v) → O_1
  43. Conic(O_1, N_1, K, M_1, J) → d_1
  44. Surface(u, (0.5 * (upper(u) + lower(u))) + ((0.5 * (upper(u) - lower(u))) * cos(v)), ((0.5 * sin(v)) * (upper(u) - lower(u)) / sqrt(1 - ecc^(2))), u, a, b, v, 0, (2 * pi)) → w

AI Drawing Prompt Reference

Draw a solid where the cross sections parallel to the yAxis are ellipses, with the minor axis lying in the base. Adjust the eccentricity to observe changes in the cross-sectional shape. The solid is composed of intersecting line segments, points, and spheres, with spheres intersecting ellipses to generate curves. These curves are then combined with other geometric objects to form the complex surface. Start by drawing the ellipses for the base and top, then generate curves from sphere intersections, and finally combine all elements to create the solid surface.
The prompt above was compiled from the original drawing commands and is for reference only.