Astro 7N Exam 1 2024/2025 Exam
Questions and Detailed Answers | Get it
100% Correct Answers
The force of gravity by the Sun keeps the planet in orbit around it, but how
do the planets affect the sun? - 🧠ANSWER ✔✔They exert an equally
strong pull on the sun, causing it move slightly
Newton's First Law - 🧠ANSWER ✔✔An object at rest stays at rest and an
object in motion stays in motion with the same speed and in the same
direction unless acted upon by an unbalanced force.
ex: if the sun suddenly disappeared, the Earth would continue in the
direction that it was traveling in its orbit at that time
Newton's Second Law - 🧠ANSWER ✔✔The acceleration of a body due to
a force will be in the same direction as the force, with magnitude directly
proportional to its mass
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,Force = mass x acceleration
A smaller mas will move faster, if the same force is applied to it
Newton's Third Law - 🧠ANSWER ✔✔For every action there is an equal
and opposite reaction
The Sun exerts force on planets, and they orbit it - he 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 - 🧠ANSWER ✔✔the strength of gravity: 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.
More mass = more gravity.
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,- 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.
Larger separation = less gravity.
- If the radius of a planet were twice that of another, the gravity is 1 / (2) 2
= 1/4 as strong.
Putting the effects of mass and radius together, you should be able to
figure out the surface gravity of Mars, relative to the Earth.
- Mars has 1/10 the mass of the Earth and 1/2 the radius of Earth. So for
Mars,
g = (1/10) / (1/2) 2 = (1/10) / (1/4) = 4/10
Mars has a surface gravity 4/10 that of Earth. You will need to be able to do
this type of estimate for the test, given the numbers for mass and radius.
If I apply exactly the same amount of force to a pebble and a boulder, what
will happen - 🧠ANSWER ✔✔the pebble will move faster
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, 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? - 🧠ANSWER ✔✔it
would become 4 times weaker
Mass - 🧠ANSWER ✔✔As the mass of the planet increases, the jump
height does decreases by the same factor
As the mass of the planet decreases, the jump height does increases by
the same factor
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 acceleration - 🧠ANSWER ✔✔acceleration increases
If the earth were moves to half its current distance from the Sun, how would
the force of gravity by the Sun on the Earth change - 🧠ANSWER ✔✔it
would become four times weaker
What did newton's law of universal gravitation tell us about how gravity
works - 🧠ANSWER ✔✔the force of gravity from the sun will be stronger on
object with more mass
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
Questions and Detailed Answers | Get it
100% Correct Answers
The force of gravity by the Sun keeps the planet in orbit around it, but how
do the planets affect the sun? - 🧠ANSWER ✔✔They exert an equally
strong pull on the sun, causing it move slightly
Newton's First Law - 🧠ANSWER ✔✔An object at rest stays at rest and an
object in motion stays in motion with the same speed and in the same
direction unless acted upon by an unbalanced force.
ex: if the sun suddenly disappeared, the Earth would continue in the
direction that it was traveling in its orbit at that time
Newton's Second Law - 🧠ANSWER ✔✔The acceleration of a body due to
a force will be in the same direction as the force, with magnitude directly
proportional to its mass
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
1
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,Force = mass x acceleration
A smaller mas will move faster, if the same force is applied to it
Newton's Third Law - 🧠ANSWER ✔✔For every action there is an equal
and opposite reaction
The Sun exerts force on planets, and they orbit it - he 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 - 🧠ANSWER ✔✔the strength of gravity: 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.
More mass = more gravity.
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
2
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,- 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.
Larger separation = less gravity.
- If the radius of a planet were twice that of another, the gravity is 1 / (2) 2
= 1/4 as strong.
Putting the effects of mass and radius together, you should be able to
figure out the surface gravity of Mars, relative to the Earth.
- Mars has 1/10 the mass of the Earth and 1/2 the radius of Earth. So for
Mars,
g = (1/10) / (1/2) 2 = (1/10) / (1/4) = 4/10
Mars has a surface gravity 4/10 that of Earth. You will need to be able to do
this type of estimate for the test, given the numbers for mass and radius.
If I apply exactly the same amount of force to a pebble and a boulder, what
will happen - 🧠ANSWER ✔✔the pebble will move faster
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
, 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? - 🧠ANSWER ✔✔it
would become 4 times weaker
Mass - 🧠ANSWER ✔✔As the mass of the planet increases, the jump
height does decreases by the same factor
As the mass of the planet decreases, the jump height does increases by
the same factor
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 acceleration - 🧠ANSWER ✔✔acceleration increases
If the earth were moves to half its current distance from the Sun, how would
the force of gravity by the Sun on the Earth change - 🧠ANSWER ✔✔it
would become four times weaker
What did newton's law of universal gravitation tell us about how gravity
works - 🧠ANSWER ✔✔the force of gravity from the sun will be stronger on
object with more mass
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
