Orbital Motion- Phy-Chem Test

- A quick review on Keplers law & Orbital Motion

Solid Assignments/Notes

Define Astronomy

* The study of the universe which includes the following
* Properties of objects in space
* Laws that predict the way the universe operates/works

Aristotle from what time did he live?

(600 B.C - 150 A.D)

Aristotle concluded what?

* That the Earth is shaped like a sphere

What was his evidence?

* Earth casts a curved shadow

What is the Geocentric model?

* That Earth was orbited by other planets

Who establish the 1st idea of the Geocentric model?

Ptolemy

Aristarchus period of life

(312 B.C - 230 B.C)

What did he propose or introduced?

* The Heliocentric model

What is the Heliocentric model?

* That the Sun is the center of the solar system and any nearby planet or thing orbits it

Claudius Ptolemy discovered what?

* The retrograde movements
* He called smaller circles epicycles

What is Retrograde?

* A directed or moving backward movement

Who is Nicolaus Copernicus?

* The first to create a detailed Heliocentric model

He was the first to propose what?

* Earth is a planet
* Earth orbits the sun annually
* Earth rotates daily on its own axis

What did Tycho Brahe did? and who hired him?

* Built many instrument that measured the locations of planets and stars
* He was hired by Johannes Kepler as an assistant

Johannes Kepler (The most important section starts here!)

From here and after its the most important things to know for the test!!!!

When was Johannes Kepler born and his death?

1571 - 1630

what did Johannes Kepler discover?

* The 3 Laws of Planetary Motion

why was it risky for Kepler to support Copernicus heliocentric model?

* Because the Lutheran & Catholic Churches don’t support this and have put Galileo under arrest

What is Kepler’s 1st Law of Planetary Motion?

* The path around the sun is an ellipse

What is an ellipse?

* It is not a perfectly circle but instead an oval shape called an ellipse

What does an ellipse contain?

* Two foci
* The sun is at 1 focus
* The other focus is symmetrically located at the opposite end of the ellipse

What does the distance between 2 foci determine?

* The shape of the ellipse
* The father apart, the longer
* And even the eccentric of the ellipse

What else does Kepler’s Law say?

* That Eliipses have eccentricity

How is eccentric measured?

* How elongated it is, therefore a clones circle is measured from the foci to the length of the major longer axis

A perfect circle has an eccentricity of?

Zero

Ellipses can have a value of what?

0\.1 - 1

Kepler’s 2nd Law of Planetary Motion

* The idea that the when a planet is closer to the sun, the faster it becomes

What is Perihelion?

* The point in a planet’s orbit closest to the sun

What is aphelion?

* The point in a plant’s orbit farthest away from the sun

Kepler’s 2nd Law also states what?

* A connecting line to the sun sweeps over equal areas in equal time intervals

Why can distance affect two objects?

* The distance changes the force of gravity
* E.G - As distance increases, the force of gravity decreases causing a planet to move slower in aphelion

What does Kepler’s 3rd Law of Planetary Motion say?

* The closer a planet is to the sun, the shorter the orbital period is

What is the orbital period for Earth?

* 1 Year

What are Astronomical Unites?

* Are used to measure distances in our solar system

What does Kepler’s 3rd Law of Planetary Motion say?

* The closer a planet is to the sun, the shorter the orbital period

To wrap up, state all of Kepler’s Law

* Kepler 1st (The path around the sun is an ellipse, and ellipse have eccentricity)
* Kepler 2nd (The closer a planet is the sun, the faster it becomes, and equal areas in equal time intervals)
* Kepler 3rd (The closer a planet is to the sun, the shorter the orbital period is)

Phy-Chem Kahoot Test

This is also crucial to the Phy-Chem Test, However the next flashcards are based on the Kahoot

Planets orbit in the shape of an ellipse. Which Kepler’s law is this?

* 1st Law of Planetary Motion

Which astronomer altered the geocentric model with epicycles to explain retrograde motion?

Ptolemy

Which astronomer designed a telescope & discovered the moons of Jupiter?

Galileo

Which astronomer believed that gravity and inertia keep the planets in orbit?

Newton

Who made accurate measurements of objects in space before the invention of a telescope?

Tycho Brahe

Which astronomer developed the 1st detailed Heliocentric model of the solar system?

* Copernicus

Which astronomer believed in a Geocentric model of the solar system?

Ptolemy

What was the missing force in Kepler’s 3rd Law of Planetary Motion that Newton later discovered?

* Gravity

Which astronomer discovered sunspots and the sun’s rotational period?

* Galileo

At what point in orbit will a planet speed up?

* Perihelion

What two factors affect the gravitational pull of an object?

* Mass and distance

An astronomical unit is the distance from the __ __to the _____

Earth and Sun

Which planet has the shortest orbital period?

* Mercury

Every object attracts every other object. This is….

* Newton’s Law of Universal Gravitation

Which astronomer was the 1st to say that the Earth is shaped like a sphere?

* Aristotle