Why do we have seasons on earth?
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
What conditions are required for a lunar eclipse?
The phase of the moon must be full, and the nodes of the moons orbit must be nearly aligned with earth and the sun
Keplers second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times, means that
A) A planet travels faster when it is nearer to the sun and slower when it is farther from the sun.
What conditions are required for a solar eclipse?
B) The phase of the moon must be new, and the nodes of the moons orbit must be nearly aligned with earth and the sun
Why do we see essentially the same face of the moon at all times
Because the moons rotational and orbital periods are equal
All of the following statements are true. Which one explains the reason why there is not a solar eclipse at every new moon?
The orbital plane of the moon is tilted by about 5 degrees to the elliptic plane
According to the universal law of gravitation, if you double the masses of both attracting objects, then the gravitational force between them will
Increase by a factor of 4
Which of the following has your address in the correct order
You, earth, solar system, Milky Way, local group, local super cluster
According to the universal law of gravitation, the force due to gravity is
Inversely proportional to the square of the distance between objects
Why is it summer in the northern hemisphere when it is winter in the southern hemisphere?
The northern hemisphere is tilted toward the sun and receives more direct sunlight
All of the following statements are true. Which one follows directly from Keplers third law?
Venus orbits the sun at a slower average speed than mercury
By locating the north celestial pole in the sky, how can you determine latitude?
The altitude of the NCP is the same as your latitude
What happens to energy in the convection zone of the sun?
energy is transported outward by the rising of hot plasma and the sinking of cooler plasma
What happens when the gravity of a massive star is able to overcome neutron degeneracy pressure
the core contracts and becomes a black hole
suppose you put two protons near each other because of the electromagnetic force the two protons will
repel each other
how does a 1.2 solar mass white dwarf compare to a 1.0 solar mass white dwarf
it has a smaller radius
on a h-r diagram where on the main sequence would we find stars that have the greatest mass?
what is a planetary nebula?
the expanding shell of gas that is no longer gravitationally held to the remnant of a low mass star
which of the following sequences correctly describes the stages of life for a low mass star?
protostar, main sequence, red giant, white dwarf
why is there an upper limit to the mass of a white dwarf
the more massive the white dwarf the greater the degeneracy pressure and the faster the speeds of the electrons. near 1.4 solar masses the speeds of the electrons approach the speed of light so more mass cannot be added without breaking the degeneracy pressure
two stars both lie on the main sequence star x is a spectral type a while star y is spectral type g therefore star x is more massive than star y