ASTRO 101 END TERM EXAM QUESTIONS
WITH DETAILED VERIFIED ANSWERS
Melanoheliophobia
An irrational fear of black holes
What are the three main attributes of photons?
Frequency, Wavelength, Energy
If a photon's frequency is increased by a factor of two, what happens to its wavelength?
Its wavelength decreases by a factor of two
If a photon's wavelength is increased by a factor of two, what happens to its frequency?
Its frequency is decreased by a factor of two
If a photon's wavelength is increased by a factor of two, what happens to its energy?
Its energy is decreased by a factor of two
The regions of the electromagnetic spectrum in order of increasing energy
Radio, infrared, visible, ultraviolet, x-rays, gamma rays
What is incandescence?
The emission of electromagnetic radiation from a hot body as a result of its temperature.
What is luminescence?
The emission of light by a substance that has not been heated, as in fluorescence and
phosphorescence.
What is the Doppler effect?
The Doppler effect occurs when a source of sound or light is moving relative to someone
observing it
If a light source moves toward you, what would you observe?
, You would observe blue-shifted light
You observe that light from a star has a longer wavelength than expected. What is a
possible explanation?
The star may be moving away from you
What effect does gravity have on light?
Gravity bends the path that light follows
Two stars are near each other, and experience gravitational force between them. What
happens if the distance between them is decreased by a factor of two?
The gravitational force increases by a factor of four
Two stars are near each other, and experience gravitational force between them. What
happens if the mass of one star is increased by a factor of two?
The gravitational force increases by a factor of two
Two stars are near each other, and experience gravitational force between them. What
does Newton's third law say about them?
The stars each experience the same force, but in opposite directions
What is weight?
Weight is the apparent force due to gravity as something is pulled against a planet's surface
If a thing is initially at rest, what happens to its kinetic energy as it is gravitationally pulled
toward a massive object
Its gravitational potential energy is changed into kinetic energy
When does an object have "escape velocity"?
Escape velocity is when an object has enough kinetic energy to escape a gravitational field
What is a dark star?
A dark star has a surface escape velocity equal to the speed of light
WITH DETAILED VERIFIED ANSWERS
Melanoheliophobia
An irrational fear of black holes
What are the three main attributes of photons?
Frequency, Wavelength, Energy
If a photon's frequency is increased by a factor of two, what happens to its wavelength?
Its wavelength decreases by a factor of two
If a photon's wavelength is increased by a factor of two, what happens to its frequency?
Its frequency is decreased by a factor of two
If a photon's wavelength is increased by a factor of two, what happens to its energy?
Its energy is decreased by a factor of two
The regions of the electromagnetic spectrum in order of increasing energy
Radio, infrared, visible, ultraviolet, x-rays, gamma rays
What is incandescence?
The emission of electromagnetic radiation from a hot body as a result of its temperature.
What is luminescence?
The emission of light by a substance that has not been heated, as in fluorescence and
phosphorescence.
What is the Doppler effect?
The Doppler effect occurs when a source of sound or light is moving relative to someone
observing it
If a light source moves toward you, what would you observe?
, You would observe blue-shifted light
You observe that light from a star has a longer wavelength than expected. What is a
possible explanation?
The star may be moving away from you
What effect does gravity have on light?
Gravity bends the path that light follows
Two stars are near each other, and experience gravitational force between them. What
happens if the distance between them is decreased by a factor of two?
The gravitational force increases by a factor of four
Two stars are near each other, and experience gravitational force between them. What
happens if the mass of one star is increased by a factor of two?
The gravitational force increases by a factor of two
Two stars are near each other, and experience gravitational force between them. What
does Newton's third law say about them?
The stars each experience the same force, but in opposite directions
What is weight?
Weight is the apparent force due to gravity as something is pulled against a planet's surface
If a thing is initially at rest, what happens to its kinetic energy as it is gravitationally pulled
toward a massive object
Its gravitational potential energy is changed into kinetic energy
When does an object have "escape velocity"?
Escape velocity is when an object has enough kinetic energy to escape a gravitational field
What is a dark star?
A dark star has a surface escape velocity equal to the speed of light
