Compare an amateur telescope of 100 mm (a typical "4-inch" telescope, usually a refractor) with that of the Keck telescope, which is 10...
View the step-by-step solution to:

Question

Stuck on questions 2 and 3, see attachment


Screen</h1><p class='abPRemoveTitle'> Shot 2020-01-06 at 4.14.02 PM.png

Screen Shot 2020-01-06 at 4.14.02 PM.png

2. Compare an amateur telescope of 100 mm (a typical &quot;4-inch&quot; telescope, usually a refractor) with that of the Keck telescope,
which is 10 meters across. [Hint: Work in powers often; &quot;2 decimals&quot; means after the decimal point in powers of ten notation.]
(a) Area of 100-mm objective in mm:
mm [Write in scientific notation and round to 2 decimals; same for part b]
(b) Area of 100-mm objective in m':
m' (Careful! Note the conversion from millimeters to meters. Working
with powers of ten can make this step easier. Hint: How many mm in 1 meter? How many mm in 1 m ?) [Round to 2 decimals]
(c) Area of 10-m Keck objective:
m [Write answer in scientific notation and round to 2 decimals]
(d) 10-m objective collects
times the light of a 100-mm objective [Round to nearest whole number]
(e) The answer to (d) represents how many magnitudes?
(Hint: Look for the x&quot; function on a scientific calculator. If (2.512) = 100 and represents 5 magnitude steps, then how
many steps does the answer to d represent? If 100 = 10 x 10 or 102, then how many powers of ten is the answer to d?)
3. A quicker way to calculate light-gathering power is to use the formula:
LGP
LGP
D.
[ Hint: Don't forget that on the right side the values are squared after being divided.]
where LGPA and LGPe are the light-gathering powers of A and B, respectively, and DA and De are the diameters of objectives A
and B. respectively. If the human eye has a diameter of 8 mm (actually the pupil of the eye), and we have both a 50-mm telescope
and a 203-mm telescope, how much more light will the telescopes gather than our eye? [Round answers to nearest whole number]
(a) LGPsom/LGPeye =
times more light
(b) LGP20 mm/LGPye =
times more light

Top Answer

2. (a) Area of 100-mm objective is 7 . 8 5 1 0 3 m m 2 (b) Area of 100-mm objective in m 2 is ... View the full answer

Sign up to view the full answer

Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

  • -

    Study Documents

    Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

    Browse Documents
  • -

    Question & Answers

    Get one-on-one homework help from our expert tutors—available online 24/7. Ask your own questions or browse existing Q&A threads. Satisfaction guaranteed!

    Ask a Question