Astro-1 Unit-1 Review Notes.pdf - Astro 1: Astronomical...

Astro 1: Astronomical Universe
Review Notes for Unit 1
In addition to these notes, refer to the game's companion "Encyclopedia," for Unit 1:
Information on the test itself
( "Test 1" covers Unit 1 )
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50 multiple-choice questions (5 answer choices each)
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The questions will relate to material from each of seven topics in Unit 1 —
Gravity, Seasons, Moon Phases, Constellations, Light, Spectroscopy, and Telescopes.
•
Some questions will be identical to those given in the game material — selected
from "Copper’s" quiz questions and those in with the lessons' dialogue
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Some questions will be drawn directly from the "Test-1 Sample Questions" packet
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Additional questions similar in nature to questions you have seen before
BE CAREFUL — Although we are not intentionally being tricky, some questions will be
similar to ones you have seen, but you need to read carefully. For example: we might ask
something about solar eclipses on the test similar to a question you may have seen about
lunar eclipses, before.
Again: be sure read each question, carefully.
This document contains an overview of things that you should take away from Unit 1 to
prepare for the first test. These are the major points, but of course the game material gives
more detail and explanation.
Remember that you can review material by starting the game, selecting the Pause Menu
pressing either the [escape] or [P] key during the game, and selecting “ Repeat a Lesson .”
You can also retry Copper’s quiz questions by finding him in the lobby of the dorm
building in the underground portion of the Mars colony; use the Pause Menu's " Maps "
screen to travel there quickly — or between other key locations in the game (tapping the
[M] key during the game also gives access to the fast-travel map).
1

1. Gravity
Newton’s Laws
1.
An object at rest, or in motion in a straight line at a constant speed, will remain in
that state unless acted upon by a force.
•
( example : If the Sun suddenly disappeared, the Earth would continue in the
direction that it was traveling in its orbit at that time.)
2.
The acceleration of a body due to a force will be in the same direction as the force,
with a magnitude inversely proportional to its mass.
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Force = mass x acceleration (or, F = m a )
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alternatively : a = F / m
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(A smaller mass will move faster, if the same force is applied to it.)
3.
For every action, there is an equal and opposite reaction.
•
(The Sun exerts force on planets, and they orbit it — the planets exert equal
force on Sun, but it only moves slightly because of its very large mass relative
to the planets.)
Surface Gravity on a Planet
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The strength of gravity, g , on the surface of a planet is given by
g =
M /
R
2
where M is the mass of the planet and R is its radius. Note the radius is squared but
the mass is not.