Upgrade to remove ads
Astro 101 Final Exam
Terms in this set (36)
During a new moon approximately what fraction of the moon is illuminated by the sun?
Where are you on Earth if the stars rise and set perpendicular to the horizon?
Where are you on Earth if the stars circle the sky parallel to the horizon?
North or South Pole
Where are you on Earth if I'm the course of the year, all stars are visible?
Where are you on Earth if the Sun rises on September 23 and does not set until March 21?
The moon shows phases in the course of a month because:
The angle the Moon makes with the Sun changes and we see different amounts of reflected light
To stop our planet from having significantly different seasons, we would have to change:
The tilt of its axis
If the Sun sets directly to the west on a certain day as seen from Valpo, what day could it be?
The first day of spring or fall
Orion is visible on winter evenings but not summer evenings because:
The location of the Earth in its orbit
Galileo's discoveries with the telescope included:
The moons of Jupiter, the phases of Venus, the mountains on the moon, spots on the Sun
When a planet, in its orbit, is closer to the Sun, it:
Moves faster than average
A scientific theory:
Must explain a wide range of observations of experiments, even the strongest theories cannot be proven beyond all doubt
A scientific theory is NOT:
just an educated guess
What is angular momentum:
Mass in circular motion
Newton's First Law (constant velocity in the absence of an external force) tells us that:
There must be a force acting between the Sun and a planet to keep the planet in orbit
Suppose a lunar eclipse is occurring on the night side of Earth. At the same time, on the day side of the Earth where the Sun is directly overhead, people are experiencing:
Astronauts float around in the space shuttle instead of falling because:
The shuttle is falling around Earth and everything aboard is in free fall
What are the two principle advances of telescopes over eyes?
Telescopes can collect far more light with far better resolution
The observed changes in wavelengths due to the Doppler effect is:
Shifted toward shorter wavelength if the object is moving toward us
Rank the types of spectra in order of increasing wavelength
Gamma rays, x-rays, ultra-violet, visible, infrared, radio waves
Which type of spectra travels through space the fastest:
They all travel through space at the same speed
How is an absorption line formed?
If light from a hot source passes through a cooler gas cloud, atoms in the cloud absorb light at wavelengths that are determined by the cloud's composition and temperature.
How could one find the temperature of a distant star?
One could find the temperature of a distant star by assuming that it's emission is approximately thermal emission, and look at its spectra. Use Wein's law to measure the temperature from the peak wavelength, and then use the Stefan-Boltzmann law to reduce the radius from your measured temperature and the total power.
What are Kepler's 3 laws of motion?
1. Planets orbit in ellipses, or oval shapes
2. Planets sweep out equal area in equal time
3. P(years)^2 = a(AU)^2
What physical properties does the gravitational force between two objects depend on?
The gravitational force between two objects depends on the mass of both objects and the distance between them.
What is the formula for gravitational force?
F = GMm/r^2
What does it mean to say that angular momentum is conserved? Give an example.
The total angular momentum of a system does not change. For example, Kepler's second law represents this. As a planet of constant mass's radius decreases, its velocity increases in order for its angular momentum to stay constant.
What kind of physical sources could produce a thermal spectrum with superimposed emission lines?
A thermal spectrum with superimposed emission lines could be produced by a star, warm person, or an incandescent light bulb. The emission lines could be produced by a nearby nebulous cloud.
How can we determine the composition of the atmosphere of stars?
Every kind of atom or molecule only has specific energies for its electrons. This means that each molecule or atom only absorbs or emits certain frequencies. Allowed frequencies are different for each atom due to the atom or molecule's chemical fingerprint. We can compare these chemical fingerprints in the Sun to what we expect from the lab to determine the composition of the gas cloud around the Sun.
What causes the apparent retrograde motion of the planets?
As Earth passes another planet, the planet appears to move backward with respect to the background stars. The planet's true motion does not change.
Suppose you go outside at midnight and notice that the moon is just setting. What would be the phase of the moon?
Why are the constellations visible at night in the spring different from the constellations visible at night I'm the fall?
The location of Earth in its orbit
What is stellar parallax?
It describes the fact that stars are actually moving relative to one another, even though to our eyes the stars appear fixed in constellations.
Suppose a solar eclipse is occurring on the day side of Earth. At the same time, on the night side of the Earth around midnight, people are experiencing:
a neap tide
If you halve the distance between two masses, the gravitational force between them:
Strengthens by a factor of 4.
If one travels from the equator headed north, the North Star, Polaris:
Moves higher in the sky
YOU MIGHT ALSO LIKE...
Astronomy ch. 1-5
Astronomy Exam 1
OTHER SETS BY THIS CREATOR
Deviance Exam 3
Delinquency Exam 1: Chapters 1-4
Crim Theory- Exam 1
OTHER QUIZLET SETS
final exam AP
Social Psych Final
PBL TUTOR SESSION 3
Galatians Chapter 3