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Astronomy 101 Exam #1
Chatpers 1-5
40
Astronomy
03/04/2012

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Term
The force of gravity is an inverse square law. This means that if you double the distance between two large masses the gravitational force between them
Definition
Weakens by a factor of 4.
Term
How does the Space Shuttle take off?
Definition
Hot gas shoots out from the rocket, and by conservation of momentum the shuttle movies in the opposite direction.
Term
Considering Einstein's famous equation E=mc2 which of the following statements is true?
Definition
A small amount of mass can be turned into a large amount of energy
Term
A skater can spin faster by pulling her arms closer to her body or spin slower by spreading her arms out from her body. This is due to
Definition
Conservation of angular momentum
Term
Kepler's third law, p2=a3 means that
Definition
Planets that are farther from the Sun move at slower average speeds than nearer planets.
Term
In which of the following cases would you feel weightless?
Definition
While falling from a roof.
Term
If your mass is 60kg on Earth, what would your mass be on the Moon?
Definition
60kg
Term
What quantities does angular momentum depend upon?
Definition
Mass, velocity, and radius
Term
What does temperature measure?
Definition
The average kinetic energy of particles in a substance.
Term
Grass (that is healthy) looks green because
Definition
It reflects green light and absorbs other colors.
Term
The wavelength of a wave is
Definition
The distance between two adjacent peaks of the wave
Term
From lowest energy to highest energy which of the following correctly orders the different categories of electromagnetic radiation?
Definition
Radio, infrared, visible light, ultraviolet, X rays, gamma rays.
Term
Which of the following statements about X rays and radio waves is NOT true?
Definition
X rays travel through space faster than radio waves.
Term
We can see each other in the classroom right now because we
Definition
Reflect visible light
Term
Which of the following statements about electrical charge is true?
Definition
A positive charge and a negative charge will attract each other
Term
When an atom loses an electron it becomes
Definition
Ionized
Term
Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. If it is doubly ionized, what is the charge of the gold ion and how many electrons remain in the ion?
Definition
The gold ion has a charge of +2 and 77 electrons.
Term
How can an electron in an atom lose energy to go from a higher energy level to a lower energy level?
Definition
It releases a photon equal in energy to its own energy drop.
Term
When light passes through a cool cloud of gas, we see
Definition
An absorption line spectrum
Term
From laboratory measurements we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanometers. The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 485.9 nm. What can we conclude?
Definition
The star is moving toward us.
Term
About where is our solar system located within the Milky Way Galaxy?
Definition
About two-thirds of the way from the center of the galaxy to the out-skirts of the galactic disk.
Term
What do we mean we we say that the universe is expanding?
Definition
Average distances are increasing between galaxies.
Term
Science shows the age of the universe to be
Definition
Between 12 billion and 15 billion years
Term
Earth is made mostly of metals and rocks. Where did this material come from?
Definition
It was produced by nuclear fusion in stars and supernova explosions.
Term
Suppose we look at a photograph of many galaxies. Assuming that all galaxies formed at about the same time, which galaxy in the picture is the youngest?
Definition
The one that is farthest away.
Term
What is the Sun mainly made of?
Definition
Hydrogen and helium
Term
The observable universe is the same size today as it was a few billion years ago
Definition
False
Term
What is an astronomical unit?
Definition
The average distance from Earth to the Sun
Term
From the fact that virtually every galaxy is moving away from us and more distance galaxies are moving away from us at a faster rate than closer ones we conclude that
Definition
The universe is expanding
Term
What is the ecliptic
Definition
The Sun's apparent path along the celestial sphere
Term
What is a circumpolar star?
Definition
A star that always remains above your horizon
Term
Orion is visible on winter evenings but not summer evenings because of
Definition
The location of Earth in its orbit
Term
Why do we have seasons on Earth?
Definition
As Earth goes around the Sun and Earth's axis remains pointed toward Polaris, the Northern and Southern hemispheres alternately receive more and less direct sunlight
Term
If the Moon is setting at 6Am the phase of the Moon must be
Definition
Full
Term
Why do we see essentially the same face of the Moon at all times?
Definition
Because the Moon's rotational and orbital periods are equal
Term
The names of the seven days of the week are based on the
Definition
Seven naked eye objects that appear to move among the constellations
Term
What do the structures of Stonehenge, the Templo Mayor, the Sun Dagger, and the Big Horn Medicine Wheel all have in common?
Definition
They were all used by ancient peoples for astronomical observations
Term
He discovered that the orbits of planets are ellipses
Definition
Kepler
Term
He discovered that Jupiter has moons
Definition
Galileo
Term
Kepler's second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times means that
Definition
A planet travels faster when it is nearer to the sun and slower when it is farther from the Sun