Posted by Art on October 23, 1997 at 07:55:51:
In Reply to: Sample Midterm Questions posted by Amy on October 22, 1997 at 16:58:09:
: 1. My friend and I were confused about question #3. Couldn't a parsec be used to measure the distance of a star or the light travel time, since they are related? Isn't measuring in parsecs interchangeable with measuring in light-years? Could you clarify?
: 2. Do stars, planets, the sun and the moon all move from east to west across the sky? Can you explain question 25?
: Thank you for your help.
: Amy Messigian
1. Light travel time and distance are related by the speed of light, but parsec specifically measures distance, not time.
2. The rotation of the Earth causes all objects to appear to move from east to west across the sky, but the Sun, Mon, and planets all move from west to east through the stars except for
a. retrograde motion of the planets
b. a few exceptions of moons that revolve or rotate in retrograde
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