Gravity, Satellites and Elliptical Orbit

Question 1

Just to recap, what is gravity exactly? 0-0

Answer 1

Gravity is a fundamental force of nature that pulls (attracts) two objects toward each other.

Question 2

So, what is a gravitational field?

Answer 2

It’s a region in space surrounding a mass where other masses experience a force of attraction (gravity).

Question 3

Can you draw a gravitational field with a smaller mass (test mass) and a larger mass, and indicate the direction of gravitational force?

Answer 3

SLAYYYY

Question 4

What’s the concept of gravitational field?

Answer 4

An object with mass will experience a gravitational force if it’s within a gravitational field of another mass

Question 5

Finish the sentence! Let’s say small planet SY is nearby larger planet J

The larger mass planet J will have gravitational field….

Answer 5

stronger than than SY, which is why S Y gets pulled towards J due to gravity

Question 6

What’s the formula of gravitational field strength?

Answer 6

𝑔⃗=𝐺𝑚/𝑟^2

m is larger mass right??

Question 7

Can yall prove that Earth’s gravitational field strength is 9.80m/s^2?

Answer 7

YALL SHOULD 0-0

Question 8

What’s Newton’s Law of Universal Gravitation about?

Answer 8

Every body in the universe attracts every other body with a *force directly proportional to the product of the 2 masses *and is *inversely proportional to r^2 *(square of distance between them from the centre)

Question 9

About Newton’s Law of Universal Gravitation…

WHAT DA FORMULA?

Answer 9

F = G ((m1m2)/r^2))

Question 10

About Newton’s Law of Universal Gravitation formula…

What does G represent?

Answer 10

That’s the Universal Gravitational Constant of 6.674 x 10^-11

Question 11

What are satellites?

Answer 11

Any body that orbits a more massive object due to gravitational attraction between the two

Question 12

What’s a natural satellite?

Answer 12

Satellites that are natural like the moon orbiting the earth or the earth orbiting the sun

Question 13

What’s an artifical satellite?

Answer 13

A man-made satellite for GPS, internet, comms, military etc

Question 14

What’s the centripetal force for satellites that allow them to always be in circular orbit?

Answer 14

Gravity!!

Question 15

If satellites are at lower attitude, what should they do to keep orbit?

Answer 15

Increase their speed!

Question 16

What happens if satellites can’t be in circular orbit no more, what do they turn to?

Answer 16

They do an elliptical orbit instead!

Question 17

Why if satellites’ speed are too high, they go in elliptical orbit?

Answer 17

Because if the speed to too much, then they need more centripetal force. But centripetal force is gravity which you can’t change.

Question 18

What is the formula to help determine the speed of the satellite & how do yall derive that?

Answer 18

V = square root of (GM/r)

Question 19

Can a satellite orbit earth NOT in the centre?

Answer 19

NO! because centripetal force is directed towards the centre. If no centre -> IMPOSSIBLE girliesss

Question 20

What is an equatorial orbit?

Answer 20

An orbit that’s geostationary = to remain above the same point on Earth’s surfaces

It orbits side to side on the the Earth’s surface

Question 21

What are equatorial orbits good for?

Answer 21

Good for monitoring things, communicating

Question 22

What are equatorial orbits NOT good for

Answer 22

Taking detailed satellite images because it’s far away from surface

If are any issues -> $$$$$ to go up there and fix it

Question 23

What is a polar orbit?

Answer 23

Low earth orbits (<1000m) that have low periods of 1.5-2hrs cuz they fast

Orbits around the polar caps (up and down if yk what i mean?)

Question 24

What are polar orbits good for?

Answer 24

If combine it with many polar orbits, they can take very detailed images which is good for weather maps!

Question 25

What is Kepler’s 1st Law?

Answer 25

All planets move in elliptical orbits with the Sun at one focus, which meant the sum of the distances from any point to the two foci is constant.

Question 26

Can you draw a diagram that explains Kepler’s 1st Law?

Answer 26

YALL SHOULD 0-0

Question 27

What’s Kepler’s 2nd Law?

Answer 27

“The radius vector drawn from the Sun to a planet sweeps equal areas in equal time intervals” which means the areas are always equal in size no matter where.

Question 28

Can yall draw a diagram that explains Kepler’s 2nd Law?

Answer 28

YALL SHOULD

Question 29

In regards to Kepler’s 2nd Law

Why is it when something is near the Sun, the acceleration increases?

Answer 29

1) When it’s near the Sun, there’s more gravity force.

2) When it’s near the Sun, distance (r) between them decreases, which increases gravity force.

F = ma, when F increase, a increase
F= (Gm1m2)/r^2 , r decrease, F incre

Question 30

What’s Kepler’s 3rd Law?

Answer 30

A formula that T^2 = (4piesquaredrcubed)/GM

Question 31

In regard to Kepler’s 3rd Law

Can you use that formula for anything? 0-0

Answer 31

NO only for circular orbits