Astronomy Test- Laws & Gravity

Question 1

What is gravity measured in?

Answer 1

N = kg/m^2

Question 2

what is astronomy?

Answer 2

the scientific study of the universe

Question 3

The solar system is part of a __________.

Answer 3

galaxy

Question 4

The galaxy in which the solar system resides is called the ___________________.

Answer 4

Milky Way Galaxy

Question 5

What is the astronomical unit (definition)?

Answer 5

The average distance between the Earth and the sun.

Question 6

What is the astronomical unit (distance)?

Answer 6

approximately 150 kilometers

Question 7

What is recessional velocity?

Answer 7

Speed at which something is traveling away

Question 8

The recessional velocity is _______ related to the _______ it is from ________.

Answer 8

directly, distance, earth

Question 9

The more ______ the greater the gravity.

Answer 9

mass

Question 10

The more _________, the weaker the gravity.

Answer 10

Distance

Question 11

What is the barycenter?

Answer 11

The common center of mass around which two or more bodies revolve

Question 12

what causes things to be attracted by gravity?

Answer 12

Mass (things with mass attract)

Question 13

What is a binary star system?

Answer 13

Two stars that orbit each other

Question 14

Stars in a galaxy will sometimes _______ together because they are attracted by their _______ _______ and mass.

Answer 14

gather, mutual gravity, mass

Question 15

Who is this person?

1. Very good at making observations
2. Measurements were very accurate
3. Believed that the sun and the mood circled the Earth (this was his own model of the universe)

Answer 15

TycoBrahe

Question 16

Who is this person?

1. Assistant
2. He was not good at making observations, but he was good at taking his person’s observation and used geometry to explain the observations.
3. He followed the belief of Nicholas Copernicus who aid the sun was at the center of the universe.

Answer 16

Johannes Kepler

Question 17

What law is this?

Planets orbit in the shape of an ellipse with the start located at one focus.

Answer 17

Kepler’s law #1

Question 18

_____________ describes how close the ellipse is to the shape of a perfect circle.

Answer 18

eccentricity

Question 19

_____ eccentricity = oval shaped

Answer 19

high

Question 20

______ eccentricity = nearly a perfect circle

Answer 20

low

Question 21

What law is this?

P2=a3
P = how long it takes the planet to go around the Sun
a = the planet’s distance from the sun (the semi-major axis of the planter’s orbit)
Tells us: Planets that are far away from the Sun have longer periods than those close to the sun. They move more slowly around the sun

Answer 21

Kepler’s Law #3

Question 22

What degree is Earth tilted at an angle of?

Answer 22

23.50 degrees

Question 23

what is precession?

Answer 23

Change in direction of the axis, but without any change in tilt.

Question 24

does precession affect the seasons?

Answer 24

No

Question 25

What law is this?
A line from the plant sweeps over equal areas in equal intervals of time.
(Basically, the closer the plant is to the start, the faster it travels.)

Answer 25

Kepler’s Law #2

Question 26

Nutation occurs over an _______ year period.

Answer 26

18

Question 27

Why does earth’s rotation happen?

Answer 27

The earth is not perfectly round, but uneven like a top.

Question 28

The equator _________ out because of the gravity from the ________________ pulling on it.

Answer 28

bulges, sun and moon

Question 29

What is the formula for gravity?

Answer 29

G = Mass1 x Mass2 / Distance^2