Practise Final Exam Flashcards
When light reflects off an object, what is the relation between the angle of incidence and the angle of reflection?
Angle of incidence = angle of reflection
Suppose that 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?
The one that is farthest away
Which of the following statements about comets and asteroids is true?
Comets are balls of ice and dust
Momentum is defined as
Mass times velocity
Why do jovian planets bulge around the equator, that is, have a smashed appearance?
Their rapid rotation flings the mass near the equator outward
The core, mantle, and crust of a planet can be defined by differences in their:
Composition
Which of the following describes a major danger of interstellar travel at near light speed?
Atoms and ions in interstellar space will hit a fast moving spacecraft like a flood of dangerous cosmic rays
What do we mean when we say the universe is expanding?
All galaxies are increasingly moving away from one another
That is the acceleration of gravity on Earth?
9.8m/s2 downward
Under what circumstances can differentiation occur in a planet?
The planet must have a molten interior
The phase of matter in the Sun is
Plasma
What do we mean when we say that the Sun is in gravitational equilibrium?
There is a balance within the Sun between the outward push of pressure and the inward pull of gravity
What is the ecliptic?
The Sun’s apparent path along the celestial sphere
The Jewish calendar is kept roughly synchronized with a solar calendar by:
Adding a thirteenth lunar month to 7 out of every 19 years
What is differentiation in planetary geology?
The process by which gravity separates materials according to density
Which of the following is a principal in advantage of CCDs over photographic film?
CCDs capture a much higher percentage of the incoming photons than does film
An icy leftover planetesimal orbiting the Sun is
A comet
In the late 1800s, Kelvin and Helmholtz suggested that the Sun stayed hot thanks to gravitational contraction. What was the major drawback of this idea?
It predicted that the Sun could last only about 25 million years, which is far less than the age of Earth
Grass appears green because
It reflects green light and absorbs other colours
What two factors are balanced in what we call gravitational equilibrium?
Outward pressure and inward gravity
Which of the following best explains why an interstellar ramjet could, in theory, achieve continuous acceleration?
It collects fuel as it goes, rather than having to carry the weight of fuel along with it
Which of the following is not considered a likely solution to the question of why we are not currently aware of a galactic civilization?
The galactic civilization probably is undetectable to us because it makes use of technologies that do not obey the laws of physics
What do asteroids and comets have in common
Most are unchanged since their formation in the solar nebula
Which of the following has your “address” in the correct order?
You, Earth, solar system, Milky Way, Local Group, Local supercluster
As long as an object is not gaining or losing mass, a net force on the object will cause a change in
Velocity
Which of the following statements about galaxies is true?
Small galaxies outnumber large galaxies but large galaxies produce most of the light in the Universe
What is the Sun made of?
70 percent hydrogen, 28 percent helium, 2 percent other elements
What type of rocket engine is used by the Space Shuttle?
Chemical rocket
Which of the following does not yield information on jovian planet interiors?
Spectroscopy of the cloud layers
The most metal-rich terrestrial planet is
Mercury
At about what fraction of the speed of light do today’s spacecraft travel?
1/10,000
How does the Sun’s mass compare with that of the planets?
It is a thousand times more massive than all the planets combined
A rocky leftover planetesimal orbiting the Sun is
An asteroid
At the Sun Dagger in New Mexico, a dagger-shaped beam of sunlight pierces a spiral
At noon on the summer solstice
Which of the following types of galaxies are reddest in colour?
Ellipticals
Which of the following statements does not use the term light-year in an appropriate way?
It will take me light-years to complete this homework assignment
Why is Jupiter denser than Saturn?
The extra mass of Jupiter compresses its interior to a greater extent than that of the Sun
Based on counting the umber of galaxies in a small patch of the sky and multiplying by the number of such patches needed to cover the entire sky, the total number of galaxies in the observable universe is estimated to be approximately
100 billion
Which of the following types of galaxies are most spherical in shape?
Ellipticals
Which of the following statements best describes the two principal advantages of telescopes over eyes?
Telescopes can collect far more light with far better angular resolution
Which of these is not a planet?
Pluto
How does Jupiter’s core compare to Earth?
It is about the same size but is 10 times more massive
If a material is transparent, then it
Transmits light well
If a material is opaque, then it
Absorbs most light
At present, what is the primary way that the search for extraterrestrial intelligence (SETI) is carried out?
By using radio telescopes to search for signals from extraterrestrial civilizations
Which of the following statements about circumpolar stars is true at all latitudes?
They always remain above your horizon
Which of the following statements about light focusing is not true?
The focal plane of a reflecting telescope is always located within a few inches of the primary mirror
If an object’s velocity is doubled, the momentum is
Doubled
When we look into the band of light in our sky that we call the Milky Way, can we see distant galaxies? Why or why not?
No, because the stars, gas, and dust of the Milky Way block us from seeing them, however we can see close galaxies
Where does nuclear fusion occur in the Sun?
In its core
