Astrophysics Flashcards
1
Q
Define a universe
A
large collection of billions of galaxies
2
Q
Define a galaxy
A
large collection of billions of stars
3
Q
Which galaxy is our solar system in?
A
The Milky Way
4
Q
What force keeps planets and moons orbitting ?
A
gravitational force
5
Q
Moons orbit ….
A
planets
6
Q
Planets orbit ….
A
stars
7
Q
Artificial satellites orbit the….
A
earth
8
Q
Comets orbit the …..
A
sun
9
Q
The gravitational field strength of an object depends on its …
A
mass
more massive means larger gravitational field strength
10
Q
Equation: orbital speed =
A
orbital speed = 2 pi r / T