Topic 8- Planetry Motion And Gravity

Question 1

Who put forwards the heliocentric model

Answer 1

Copernicus

Question 2

What book did Copernicus write

Answer 2

De revolutionibus orbium coelestium- on the revolutions of heavenly spheres

Question 3

What types of orbits did the planets have in Copernicus’ book

Answer 3

Circular orbits

Question 4

What type of observations supported his theory

Answer 4

Mathematical observations

Question 5

When was the book published

Answer 5

After he died

Question 6

Why did people find it hard to accept the heliocentric theory

Answer 6

It went against what the bible said

Question 7

What model did Tycho Brahe propose

Answer 7

The geo-heliocentric model

Question 8

What is the geo-heliocentric model

Answer 8

The moon and sun orbited the earth but everything else orbited the sun

Question 9

What did tychos base his model on

Answer 9

Both religious and on observations

Question 10

Who was Kepler

Answer 10

Tycho Brahe’s assistant in Prague

Question 11

Who was Kepler influenced by

Answer 11

Copernicus

Question 12

What did Kepler refine

Answer 12

The heliocentric model

Question 13

What did Kepler notice with tychos observations

Answer 13

He noticed that planets did not follow circular orbits but we elliptical

Question 14

What was Galileo Galilei first to do

Answer 14

The first telescopic observer to make published astronomical observations

Question 15

What did Galileo discover

Answer 15

Jupiter has moons
Venus had phases

Question 16

What happened because of Galileos observations

Answer 16

The heliocentric model became widely expected

Question 17

What force is responsible for creating stable elliptical orbits

Answer 17

Gravity

Question 18

How does gravity create stable elliptical orbits

Answer 18

Due to the constant gravitational force between the object and the sun to keep it in orbit

Question 19

What are the 2 things that control gravity

Answer 19

Mass and distance

Question 20

What is keplers first law

Answer 20

Planets do not move in circular orbits

Question 21

What is an ellipse

Answer 21

An oval shape with 2 foci

Question 22

What are the 2 foci

Answer 22

The sun and the other is in space

Question 23

What is keplers second law

Answer 23

The sun-planet line sweeps out equal areas in equal times

Question 24

Does a planet move faster or slower when near the sun

Answer 24

Faster

Question 25

What is keplers 3rd law

Answer 25

The orbital period of a planet squared is equal to its mean distance from sun cubed when different planets are compared

Question 26

How do you work out a constant

Answer 26

T2/R3

Question 27

What does the T stand for in the constant equation

Answer 27

Period/time takes to orbit/ orbital period

Question 28

What does the R mean in the constant equation

Answer 28

Mean radius from the body it’s orbiting

Question 29

Who proposed the inverse square law

Answer 29

Newton

Question 30

What is the inverse square law

Answer 30

If earth had a 1/2 of its mass then it would produce 1/4

Question 31

What was the relation to keplers law

Answer 31

For every action there is an equal action and opposite reaction

Question 32

If an object orbits nearer another in an elliptical orbit there must be an increase or decrease in gravitational force between them at that point

Answer 32

Increase

Question 33

What is keplers 3rd law

Answer 33

The force is proportional to the sum of the masses of both objects it inversely relies on the mass of the sun essentially

Question 34

What does perihelion mean

Answer 34

Body nearer the sun

Question 35

What does aphelion mean

Answer 35

Body further away from sun