The Moon's angular diameter in our sky is measured to be 0.5. ...

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The Moon's angular diameter in our sky is measured to be 0.5. From this, we can find
 
  a. the mass density of the Moon if we know its distance from the Earth.
  b. diameter of the Moon if we know the Moon's distance.
  c. diameter of the Moon with no other information about the Moon.
  d. distance to the Moon with no other information about the Moon.

Question 2

How can we tell that some stars are relatively close to us in the sky?
 
  a. Some stars are occasionally eclipsed by the Moon, so they must be nearby.
  b. Some stars vary in brightness caused by sunspots we can see because they are so close.
  c. Some stars appear to be extremely bright and must therefore be very close to us.
  d. Some stars appear to move periodically back and forth against the background stars because of the Earth's movement around the Sun.

[blfontai]

Answer to Question 1

B

Answer to Question 2

D

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TYSM

[cam1229]

Excellent