2007-07-16 15:25:53 · 3 answers · asked by Brilliant Queen (BQ)_forever !!! 5 in Science & Mathematics ➔ Physics
The key here is the term "focal length". The length of the refacting telescope will be around the length of the sum of the two focal points.
If this is a homemade "sliding" telescope, then the finished telescope will be slightly longer than the sum of the two focal lengths (this allows for focusing).
If this is a refracting telescope with a mirror and an eye piece, then the length of the main tube of the telescope might be slightly less than the sum of the focal lengths, but if you measure the distance that light has to travel between the first and second lens, you'll once again find the sum of the two focal lengths.
Hope this helps
2007-07-20 17:03:27 · answer #1 · answered by Kevin S 7 · 0⤊ 0⤋
Refracting telescope has one converging and one diverging lens (so that image is direct, not inverted). Its length is
Fconv - Fdivg < sum of them
2007-07-23 06:46:47 · answer #2 · answered by Alexander 6 · 0⤊ 0⤋
Double the sum.
2007-07-18 05:05:07 · answer #3 · answered by therealchuckbales 5 · 0⤊ 0⤋