Gravitation Quiz

What where questions that where answered by newton ?

What is gravity, where does it come from, how does it work

Our current understanding of gravity …

grew out of the attempt to explain and understand planetary orbits

Who was capernicus ?

Polish Astronomer

What did he do ?

Contributed to the heliocentric planetary system and raised debates about geocentric or heliocentric.

Who was Galileo Galieli …..

Italian “reinassance man”

What did he do ?

First to point in the night newly invented telecope. Found that jupiters 4 main moons that where orbiting around it. Found that objects can orbit another object other than the earth. Creator of Inertia.

What was Galileos Missed opportunity ?

Galieo still believed in the natural motion of planets, and did not think of a reason of why planets moved. However, he should have realized that planets did not move in perfect circles by themselves and that a force was needed to change their direction of motion.

Who was Tycho Brahe ?

Danish Astronomer

What was different about him …

He looked for answers outwards instead of inwards, taking a scientific aproach

What was Tycho Brahe curious about ?

He wanted to answer the debate of heliocentric and Geocentric solar systems …

How did Tycho Brahe adress what he was curious about ….

He measured the position of the 5 known visible planets for twenty years

What was his accuracy

1/60 of a degree

What did Tycho Brahe use to measure the planets ….

A Quadrant

Who was Johanned kepler

German Mathematician

What did Kepler does he do ?

Does mathematical analysis on brahes data to create a map on the positions of the planets

what did kepler do after he made the map ?

Make Keplers three laws of planetary motion

Why are keplers laws empirical ?

Because they are based on observation

What is Keplers laws of orbits ?

The orbits of the planets are ellipsis with the sun at one focus

What is an ellipse ?

The set of all points whose combined distances to two fixed point, the foci

Since the foci are inside of the ellipse, the solar system must be ..

Heliocentric

Eccentricity ….

The measure of how elongated an ellipse is

Write down the formula ……

e= root of a²-b²/a²

Law of Areas ….

The line joining a planet to the sun traces out equal areas in equal times.

What is the law saying ?

Planets speed is faster when it is closer to the sun and slower when it is further away

Law of periods

The square of the period of a planet is proportional to the cube of its average distance from the sun.

what is the equation …

T²=kR²

what is k ?

constant of proportionality

what are the measurements units of R and T

R is Astronomical Units and T is years

what is the constant of R and T ?

1