High School Challenge

Week Ending 3-7-99

Send Answer to: ucfcasio@pegasus.cc.ucf.edu

Congratulations to Frank Lee of Decatur High School in Federal Way, WA. Frank wins the Casio CFX-9850G Color Graphing calculator.

The Shadow Knows

A large sphere is on a horizontal surface on a clear, sunny day and casts a shadow that is 10 m long when measured from where the sphere touches the surface. At the same instant in time, a meter stick, placed on the surface and perpendicular to it, casts a 2 m long shadow. What is the radius of the sphere? For the sake of this problem, assume the sun's rays are parallel and that the meter stick is a line segment.

Correct Solutions:

  1. Lisa Schechner. Manorhaven ES, Port Washington, NY
  2. Xingji Zheng. Abby Senior SS, Abbotsford, BC, Canada
  3. Sorin Ionescu. John Abbott College, Montreal, Canada
  4. Farhad Roueintan. Carson Graham SS, North Vancouver, BC, Canada
  5. Cyrus Harvesf. Stanton College Prep, Jacksonville, FL
  6. Lisa Gardner. Boyette Springs ES, Riverview, FL
  7. Dina Berkovits. Bridgewater-Raritan HS, Bridgewater, NJ
  8. Laurel Maharaj. Rio Claro HS, Rio Claro, Trinidad &Tobago
  9. Timothy Johnson. Rhodesway School. Bradford. United Kingdom
  10. Jarvis Yu. Montgomery Blair HS, Silver Springs, MD
  11. Wing Lian. Oak Grove HS, Hattiesburg, MS
  12. Michael Moyer, The Way Home School, Carlisle, PA
  13. Xiao Wei Chen. WestBrook MS, Paramus, NJ
  14. Chen Lin. Mckinley HS, Honolulu, HI
  15. Daniel Keesing. Ridgewood HS, Ridgewood, NJ
  16. Henry Magana. Newport Harbor HS, Newport Beach, CA
  17. Doug Dukes. Newport Harbor HS, Newport Beach, CA
  18. Olivia Crigler. Merritt Island HS, Merritt Island, FL
  19. Eric Hoke. Wayland HS, Wayland, MA
  20. Andy Novocin. Stanton College Prep, Jacksonville, FL
  21. Daniel Yu. Randolph MS, Randolph, NJ
  22. Nasser Demir. American School of Kuwait, Hawalli, Kuwait
  23. Alice Cheng. Hunter College HS, New York City, NY
  24. Christopher Leon. Westmount SS, Hamiltion, Ontario, Canada
  25. Nishant Prasad. Liberty HS, Renton, WA
  26. Jason Juang. Sycamore JHS, Cincinnati, OH
  27. Trevor Jones, Newport Harbor HS, Newport Beach, CA
  28. Logan Axon. West HS, Salt Lake City, UT
  29. Steven Jendrusina. Newport Harbor HS, Newport Beach, CA
  30. Asher Walkover. Rambam Mesivta HS, Lawrence, NY
  31. Yu Ko-Chia. Holdingford HS, Holdingford, MN
  32. Scott Tippett. Newport Harbor HS, Newport Beach, CA
  33. Ashirul Amin. Red Cross Nordic United World College, Flekke-Fjaler, Norway
  34. Eric Allione. Newport Harbor HS, Newport Beach, CA
  35. Kayley Harrington, Newport Harbor HS, CA
  36. Brendon Hansen. Newport Harbor HS, Newport Beach, CA
  37. Guy David. Pinecrest ES, Miami, FL
  38. Justin Shih. Clear Lake HS, Houston, TX
  39. Kimberly Christensen. Newport Harbor HS. Newport Beach, CA
  40. Bill Fay. Pioneer HS, Ann Arbor, MI
  41. Yosef Polakoff. Rambam Mesivta HS, Lawrence, NY
  42. John Ku. East Leyden HS, River Grove, IL

Previous Problems

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