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Author Question: In a reflecting telescope the objective is a ____. a. prism b. mirror c. lens d. diffraction ... (Read 83 times)

sarasara

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on: Jul 27, 2018
In a reflecting telescope the objective is a ____.
 
  a. prism
  b. mirror
  c. lens
  d. diffraction grating
  e. photographic plate

Question 2

A planetary nebula has a radius of 0.5 pc and is expanding at 20 km/sec. What is the approximate age of this planetary nebula? (1 pc is equal to 3 x 1013 km and 1 year is equal to 3.15 x 107 seconds.)
 
  a. 240 years
  b. 790,000 years
  c. 96,000 years
  d. 960 years
  e. 24,000 years


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isabelt_18

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Reply #1 on: Jul 27, 2018
Answer to Question 1

B

Answer to Question 2

E


sarasara

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Reply 2 on: Jul 27, 2018
Excellent

xiazhe

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Reply 3 on: Yesterday
Wow, this really help

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