space Flashcards
(24 cards)
What are the components of a galaxy?
Stars, planets, dwarf planets, moons, asteroids and comets
What do planets, dwarf planets, and comets orbit?
Stars
What do moons orbit?
Planets
How was the sun formed?
From a nebula which was pulled together by the force of gravity
What is nuclear fusion?
The joining of two light nuclei to form a heavier nucleus
What happens to mass in nuclear fusion?
Some of the mass is converted into energy and some of this energy is emitted as radiation
What conditions are needed in order for nuclear fusion?
Nuclear fusion needs very high temperature and pressure to overcome the electrostatic repulsion of the small nuclei and to bring the positive nuclei close together enough for fusion to take place
What is the lifecycle of a star that is the same size as the sun?
nebula > protostar > main sequence star > red giant > white dwarf > black dwarf
What is the lifecycle of a star that is larger than the sun?
nebula > protostar > main sequence star > red supergiant > supernova > neutron star > black hole
Where is helium created?
All stars fuse hydrogen into helium
What elements do bigger stars produce?
They fuse helium into ligutweight elements up to and including iron
What do supernovas produce?
Elements up to uranium
What is the formation of elements called?
Nucleosynthesis
What are artificial satellites?
Man-made objects which orbit the earth
What are artificial satellites used for?
communications, GPS, weather forecasting, surveys of the Earth’s surface, map making , spying, and space explorations
How can an object be accelerating while moving at a constant speed?
When an object moves in a circle at a constant
speed, its direction constantly changes. A change in direction causes a change in velocity because velocity is a
vector quantity. A change in velocity results in acceleration
What is gravitational field strength on eart?
9.8 N/Kg
What affect does distance have on gravitational field strength?
The further a planet is, the weaker the force of gravity and the slower the planet moves
What is the big bang theory?
The Big Bang theory states that the Universe began from a very small region that was extremely hot and dense and matter and high energy radiation were released
What evidence is there that the big bang theory happened?
The universe was and still is expanding
What is the doppler effect?
The Doppler Effect states when a car moves away from the observer, the pitch of the engine decreases, and the wavelength increases. When the car moves towards the observer the pitch increases so the wavelength decreases
How are galaxies held together?
Dark matter by gravitational attraction
What is responsible for the increased rate of expansion of the universe?
Dark energy
What is red shift?
The observed increase in the wavelength of light due to the source moving away from the observer towards the red end of the light spectrum
