Astro 7n Exam 1 (Unit 1 & 2) Quiz
Questions and Answers
According to Newton's Second Law of motion, if the net force acting on the object
increases while the mass of the object remains constant, what happens to the
acceleration?
Hint: Remember F = m * a
✓ ~~~Acceleration Increases
If the earth were moved to half its current distance from the sun, how would the force
of gravity by the sun on the earth change?
Hint: Recall the form of the equation that you derived, earlier in the game:
"gravitational acceleration (g) is proportional to the mass (m) of the body you are
bound to, and INVERSELY proportional to the SQUARE of your distance (r) from its
center mass," or g = m / (r * r)
✓ ~~~It would be four times stronger
What did newton's law of universal gravitation tell us about how gravity works?
Hint: Recall that the FORCE of gravity ('F = ma' or 'F = mg'), unlike gravitational
acceleration (just the 'a' or 'g'), depends on the masses of two objects interacting --
,remember that the 'g' in 'F = mg' is also dependent on a mass value (of a second
object).
✓ ~~~The force of gravity from the sun will be stronger on an object with more mass
The earth's radius is about 6400 km. If you were to orbit in the space station 150 km
above the ground, the force of gravity you feel from earth would be...?
Hint: think only about Newton's Law of Universal Gravitation. Recall the form of the
equation that you derived earlier in the game: "gravitational acceleration (g) is
proportional to the mass (m) of the body you are bound to, and INVERSELY
proportional to the SQUARE of your distance (r) from its center mass," or g = m / (r *
r)
✓ ~~~Slightly weaker than when you are standing on earth
If you were to sit on the ground ere would be a force due to gravity pulling you
toward earth. which of the following is true according to newton's 3rd law?
Hint: Remember each force has an equal and opposite reaction.
✓ ~~~You are pushing the earth away from yourself with the same force
What would happen to the earth if the Sun's gravity somehow turned off
instantaneously?
, Hint: Recall Newton's First Law of Motion (also referred to as "inertia"): "An object at
rest will remain as rest unless acted upon by a force. An object in motion will
continue in motion --- in a straight path and at constant velocity -- unless acted upon
by a force, Think of a moment about the force of gravity between the Earth and the
Sun, and which way or ways that force is directed.
✓ ~~~It would continue to move in a line in the same direction it was moving when the
gravity turned off
Consider a planet whose rotation axis is NOT tilted with respect to its orbital plane.
What are the season's like on this planet?
Hint: The seasons on Earth aren't caused by different distances from the Sun in
different parts of the orbit. What are they caused by?
✓ ~~~There are no seasons
If the Earth rotated on its axis more slowly than it does now...
Hint: How long does it take for the Earth to rotate
✓ ~~~Its days would be longer
If Earth has its orbit changed so that at all points along its orbit it was always the
same distance from the sun (circular orbit), how would this affect the seasons on
Earth?
Questions and Answers
According to Newton's Second Law of motion, if the net force acting on the object
increases while the mass of the object remains constant, what happens to the
acceleration?
Hint: Remember F = m * a
✓ ~~~Acceleration Increases
If the earth were moved to half its current distance from the sun, how would the force
of gravity by the sun on the earth change?
Hint: Recall the form of the equation that you derived, earlier in the game:
"gravitational acceleration (g) is proportional to the mass (m) of the body you are
bound to, and INVERSELY proportional to the SQUARE of your distance (r) from its
center mass," or g = m / (r * r)
✓ ~~~It would be four times stronger
What did newton's law of universal gravitation tell us about how gravity works?
Hint: Recall that the FORCE of gravity ('F = ma' or 'F = mg'), unlike gravitational
acceleration (just the 'a' or 'g'), depends on the masses of two objects interacting --
,remember that the 'g' in 'F = mg' is also dependent on a mass value (of a second
object).
✓ ~~~The force of gravity from the sun will be stronger on an object with more mass
The earth's radius is about 6400 km. If you were to orbit in the space station 150 km
above the ground, the force of gravity you feel from earth would be...?
Hint: think only about Newton's Law of Universal Gravitation. Recall the form of the
equation that you derived earlier in the game: "gravitational acceleration (g) is
proportional to the mass (m) of the body you are bound to, and INVERSELY
proportional to the SQUARE of your distance (r) from its center mass," or g = m / (r *
r)
✓ ~~~Slightly weaker than when you are standing on earth
If you were to sit on the ground ere would be a force due to gravity pulling you
toward earth. which of the following is true according to newton's 3rd law?
Hint: Remember each force has an equal and opposite reaction.
✓ ~~~You are pushing the earth away from yourself with the same force
What would happen to the earth if the Sun's gravity somehow turned off
instantaneously?
, Hint: Recall Newton's First Law of Motion (also referred to as "inertia"): "An object at
rest will remain as rest unless acted upon by a force. An object in motion will
continue in motion --- in a straight path and at constant velocity -- unless acted upon
by a force, Think of a moment about the force of gravity between the Earth and the
Sun, and which way or ways that force is directed.
✓ ~~~It would continue to move in a line in the same direction it was moving when the
gravity turned off
Consider a planet whose rotation axis is NOT tilted with respect to its orbital plane.
What are the season's like on this planet?
Hint: The seasons on Earth aren't caused by different distances from the Sun in
different parts of the orbit. What are they caused by?
✓ ~~~There are no seasons
If the Earth rotated on its axis more slowly than it does now...
Hint: How long does it take for the Earth to rotate
✓ ~~~Its days would be longer
If Earth has its orbit changed so that at all points along its orbit it was always the
same distance from the sun (circular orbit), how would this affect the seasons on
Earth?
