Podcast
Questions and Answers
What happens to an atom when an electron is completely detached from it?
What happens to an atom when an electron is completely detached from it?
- The atom is in the ground state
- The atom is ionized (correct)
- The atom is an isotope
- The atom becomes part of a molecule
What is a requirement for an object to be considered a dwarf planet in our Solar System?
What is a requirement for an object to be considered a dwarf planet in our Solar System?
- It must be close to a round shape (correct)
- It must clear its orbit of other objects
- It must be part of a larger galaxy
- It must be a moon
How much smaller is the distance between the Sun and the nearest star compared to the distance between the Milky Way and Andromeda?
How much smaller is the distance between the Sun and the nearest star compared to the distance between the Milky Way and Andromeda?
- By a factor of 10 (correct)
- By a factor of 100
- By a factor of 1,000,000
- By a factor of 1,000
Why can we study how galaxies evolve?
Why can we study how galaxies evolve?
What is the age of the most recent information we can get about a star 50 lightyears away?
What is the age of the most recent information we can get about a star 50 lightyears away?
What are the correct standard units of mass, distance, and time?
What are the correct standard units of mass, distance, and time?
What is the duration of this examination?
What is the duration of this examination?
Where should you record your answers?
Where should you record your answers?
What is the consequence of arriving late to the examination?
What is the consequence of arriving late to the examination?
Why must you remain silent in your seat during the last 15 minutes of the examination?
Why must you remain silent in your seat during the last 15 minutes of the examination?
What is the consequence of writing on the question paper?
What is the consequence of writing on the question paper?
What is the purpose of showing your student card to the exam invigilators?
What is the purpose of showing your student card to the exam invigilators?
What is the unit of mass commonly used in astronomy?
What is the unit of mass commonly used in astronomy?
Why does the Solar System not expand apart due to the expansion of the universe?
Why does the Solar System not expand apart due to the expansion of the universe?
What is the difference in the gravitational pull of a black hole and a normal star with the same mass on a planet orbiting them at the same distance?
What is the difference in the gravitational pull of a black hole and a normal star with the same mass on a planet orbiting them at the same distance?
What is the speed of light emitted by a spaceship moving towards you at 1/3c?
What is the speed of light emitted by a spaceship moving towards you at 1/3c?
How can we measure the speed at which galaxies move?
How can we measure the speed at which galaxies move?
What is the implication of the universe expanding on the Solar System?
What is the implication of the universe expanding on the Solar System?
What would happen if we suddenly turned off gravity in the Milky Way?
What would happen if we suddenly turned off gravity in the Milky Way?
What is the Doppler Effect?
What is the Doppler Effect?
How can we determine the distance to a galaxy that contains Cepheid variable stars?
How can we determine the distance to a galaxy that contains Cepheid variable stars?
What happens to an object's mass as it approaches the speed of light?
What happens to an object's mass as it approaches the speed of light?
What can we conclude from the fact that all distant galaxies are redshifted?
What can we conclude from the fact that all distant galaxies are redshifted?
Can we measure the motion of galaxies like we do for stars?
Can we measure the motion of galaxies like we do for stars?
What happens to the light received from a distant star moving away from us compared to light from our Sun?
What happens to the light received from a distant star moving away from us compared to light from our Sun?
What must occur to an electron in orbit around an atom's nucleus for it to emit a photon?
What must occur to an electron in orbit around an atom's nucleus for it to emit a photon?
What is the correct order of the fundamental forces from strongest to weakest?
What is the correct order of the fundamental forces from strongest to weakest?
Why do observers moving at different constant velocities see time pass at different rates?
Why do observers moving at different constant velocities see time pass at different rates?
What is the result of an electron jumping from a higher energy orbit to a lower energy orbit around an atom's nucleus?
What is the result of an electron jumping from a higher energy orbit to a lower energy orbit around an atom's nucleus?
What can be said about the light emitted from our Sun and an identical distant star moving away from us?
What can be said about the light emitted from our Sun and an identical distant star moving away from us?
Flashcards
What are the standard units for mass, distance, and time?
What are the standard units for mass, distance, and time?
The standard units for measuring mass, distance, and time, respectively.
How does the gravity of a black hole compare to a star with the same mass?
How does the gravity of a black hole compare to a star with the same mass?
A black hole and a normal star with the same mass will exert the same gravitational pull on a planet orbiting them at the same distance. This is because gravity depends only on mass and distance.
What is the speed of light, and how does it relate to the motion of its source?
What is the speed of light, and how does it relate to the motion of its source?
The speed of light is constant regardless of the motion of the source or observer. This means that light from a spaceship moving towards you will still travel at the speed of light, even though the spaceship is moving quickly.
How does the distance between the Milky Way and Andromeda compare to the distance between the Sun and its nearest star?
How does the distance between the Milky Way and Andromeda compare to the distance between the Sun and its nearest star?
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How does the study of distant galaxies help us understand galaxy evolution?
How does the study of distant galaxies help us understand galaxy evolution?
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What are the criteria for an object to be classified as a dwarf planet?
What are the criteria for an object to be classified as a dwarf planet?
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What happens to an atom when it is ionized?
What happens to an atom when it is ionized?
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How is an emission line created in atomic physics?
How is an emission line created in atomic physics?
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What would happen to the Milky Way if gravity were suddenly turned off?
What would happen to the Milky Way if gravity were suddenly turned off?
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According to general relativity, what is gravity?
According to general relativity, what is gravity?
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What happens to the mass of an object as it approaches the speed of light?
What happens to the mass of an object as it approaches the speed of light?
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How does special relativity affect the perception of time for observers moving at different velocities?
How does special relativity affect the perception of time for observers moving at different velocities?
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How can we determine the distance to a galaxy containing Cepheid variable stars?
How can we determine the distance to a galaxy containing Cepheid variable stars?
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What is the correct order of the fundamental forces from strongest to weakest?
What is the correct order of the fundamental forces from strongest to weakest?
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How do we know that the Universe is expanding?
How do we know that the Universe is expanding?
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Will the Solar System eventually expand apart due to the Universe's expansion?
Will the Solar System eventually expand apart due to the Universe's expansion?
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Study Notes
Units of Measurement
- The correct standard units of mass, distance, and time are kg, m, and s.
Black Holes
- A black hole and a normal star with the same mass will exert the same gravitational pull on a planet orbiting them at the same distance.
Speed of Light
- The speed of light remains constant regardless of the motion of the source or observer.
- If a spaceship moves towards you at 1/3c, the speed of the light emitted by the spaceship, as measured in your frame of reference, is c.
Galaxies
- The distance between the Sun and the nearest star is smaller than the distance between the Milky Way and the nearest large galaxy, Andromeda, by a factor of roughly 100,000.
- We can study how galaxies evolve because the further away we look, the further back in time we see.
Dwarf Planets
- To be considered a dwarf planet, an object in our Solar System must orbit the Sun and be close to a round shape.
Atomic Physics
- If an electron is completely detached from an atom, the atom is ionized.
- When an atom emits a photon and creates an emission line, one of the electrons in orbit around the atom's nucleus has to jump from a higher energy orbit to a lower energy orbit.
Gravity
- If gravity were suddenly turned off in the Milky Way, the galaxy would fly apart.
- The theory of general relativity shows that gravity is not a force, but rather the curvature of spacetime.
Relativity
- As an object approaches the speed of light, its mass approaches infinity.
- The theory of special relativity shows that observers moving at different constant velocities will see time pass at different rates due to the fact that everyone agrees on the speed of light.
Stars
- We can determine the distance to a galaxy that contains Cepheid variable stars by using the period-luminosity relation.
Forces
- The correct order of the fundamental forces, placing the strongest first, is strong, electromagnetic, weak, and gravity.
Universe Expansion
- Because all distant galaxies are redshifted, we know that the Universe is expanding.
- If the universe is expanding, the Solar System will not eventually expand apart due to its own gravity holding it together.
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Description
Take this midterm exam to test your knowledge on astronomy topics, covering 30 multiple-choice questions in 50 minutes. The quiz is designed for students of Dr. Robert Cockcroft's ASTRON 2B03 course at McMaster University. Evaluate your understanding of the course material and identify areas for improvement.
