Astro 7N Exam 1 2024 Questions and Answers | 100%Verified and Updated.
The force of gravity by the Sun keeps the planet in orbit around it, but how do t... [Show More] he planets affect the
sun?
They exert an equally strong pull on the sun, causing it move slightly
Newton's First Law
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
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
Force = mass x acceleration
A smaller mas will move faster, if the same force is applied to it
Newton's Third Law
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
Astro 7N Exam 1 2024 Questions and Answers
| 100%Verified and Updated.
Surface Gravity on a Planet
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.
- 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
the pebble will move faster
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?
it would become 4 times weaker
Mass
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
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
it would become four times weaker
What did newton's law of universal gravitation tell us about how gravity works
the force of gravity from the sun will be stronger on object with more mass. [Show Less]
