What is the density-wave model?
A. It is a model who puts on a show at astronomy meetings.
B. It is a description of how light propagates.
C. It is a theory of the origin of the Universe.
D. It is a way of describing the formation of Galactic spiral arms.
Answer: D
You might also like to view...
The speed of light (and radio waves) is 300,000 km/s. How far away is a spacecraft if its radio signal takes 10 minutes to reach Earth?
What will be an ideal response?
A “free” electron and a “free” proton are placed in an identical electric field. Is the following statement true or false?
Both particles have the same acceleration. span>
1.False 2.TrueWhich of the following best explains the success of the central African rainfall-prediction technique of observing the waxing crescent Moon?
A) When the Moon is aligned in a U-shape, it can hold more water, so there is more rain. When it is tilted, it can hold less, so the weather is drier. B) When the Moon is in Capricorn, there is always more tempestuous weather, while when in Pisces, it is just plain rainy. C) Clouds cover part of the Moon's surface, so the smaller the crescent, the more likely it is to rain. D) The Moon's orientation varies seasonally, and so does the weather. E) The Moon causes the tides and affects the weather.
Two stars have the same spectral type. Star X is in luminosity class III, while Star Y is in luminosity class V. Star X must be larger in radius than Star Y
Indicate whether the statement is true or false