ASTRO 7N EXAM 1 INTRODUCTION TO
ASTRONOMY ACTUAL STUDY GUIDE
QUESTIONS AND SOLUTIONS 2026
COMPREHENSIVE REVIEW PACK
◉ Newton's Second Law
Answer: 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.
(Usually written F=ma, Force= mass x acceleration)
◉ Newton's Third Law
Answer: For every action, there is an equal and opposite reaction
◉ Newton's Law of Universal Gravitation
Answer: This law gives the force of gravity between any two objects
in the Universe. The force of gravity is proportional to (mass of
object 1) × (mass of object 2) divided by the distance between the
two objects squared:
◉ Strength of force equation
,Answer: Fg = G (m1 m2)/r2
◉ More mass=more gravity
Answer: If the mass of a planet were twice that of another, but they
had the same radius, the gravity felt on the surface of the more-
massive one would be twice as strong
◉ Large separation=less gravity
Answer: If the radius of a planet were twice that of another, the
gravity is 1/(2)2= 1/4 as strong
◉ Gravitational Force
Answer: Directly proportional to the mass of each interacting object
and inversely proportional to the distance between them squared
◉ Summer = December
Winter = June
Answer: Seasons in the southern hemisphere
◉ Dark all day/ Night at south pole
Answer: June
, ◉ the Earth would continue in the direction that it was traveling in
its orbit at that time
Answer: If the sun suddenly disappeared
◉ the planets exert equal force on Sun, but it only moves slightly
because of its very large mass relative to the planets
Answer: The Sun exerts force on planets, and they orbit it
◉ If the mass of a planet were twice that of another, but they had the
same radius,
Answer: the gravity felt on the surface of the more-massive one
would be twice as strong.
◉ Rotation of the earth on its axis
Answer: What causes day and night
◉ East to West because of Earth's rotation. The stars and planets
move in the same way from our point of view, also because of earths
rotation
Answer: How does the sun appear to move in the sky in the course
of the day?
◉ It orbits the sun, once
Answer: What happens to the earth in one year
ASTRONOMY ACTUAL STUDY GUIDE
QUESTIONS AND SOLUTIONS 2026
COMPREHENSIVE REVIEW PACK
◉ Newton's Second Law
Answer: 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.
(Usually written F=ma, Force= mass x acceleration)
◉ Newton's Third Law
Answer: For every action, there is an equal and opposite reaction
◉ Newton's Law of Universal Gravitation
Answer: This law gives the force of gravity between any two objects
in the Universe. The force of gravity is proportional to (mass of
object 1) × (mass of object 2) divided by the distance between the
two objects squared:
◉ Strength of force equation
,Answer: Fg = G (m1 m2)/r2
◉ More mass=more gravity
Answer: If the mass of a planet were twice that of another, but they
had the same radius, the gravity felt on the surface of the more-
massive one would be twice as strong
◉ Large separation=less gravity
Answer: If the radius of a planet were twice that of another, the
gravity is 1/(2)2= 1/4 as strong
◉ Gravitational Force
Answer: Directly proportional to the mass of each interacting object
and inversely proportional to the distance between them squared
◉ Summer = December
Winter = June
Answer: Seasons in the southern hemisphere
◉ Dark all day/ Night at south pole
Answer: June
, ◉ the Earth would continue in the direction that it was traveling in
its orbit at that time
Answer: If the sun suddenly disappeared
◉ the planets exert equal force on Sun, but it only moves slightly
because of its very large mass relative to the planets
Answer: The Sun exerts force on planets, and they orbit it
◉ If the mass of a planet were twice that of another, but they had the
same radius,
Answer: the gravity felt on the surface of the more-massive one
would be twice as strong.
◉ Rotation of the earth on its axis
Answer: What causes day and night
◉ East to West because of Earth's rotation. The stars and planets
move in the same way from our point of view, also because of earths
rotation
Answer: How does the sun appear to move in the sky in the course
of the day?
◉ It orbits the sun, once
Answer: What happens to the earth in one year
