Astro 101 Final Exam Questions And Answers 100% Pass
The Special Theory of Relativity - ✔✔✔1. All motion is relative: no special frame of reference exists from which an absolute standard of motion can be judged
2. The speed of light is the same for all observers, no matter what their state of motion
Einstein's theory of General Relativity predicts that
a. lengths appear to contract for moving objects
b. stars should collapse into black holes
c. gravity is caused by curved spacetime
d. time appears to slow for moving objects - ✔✔✔c. gravity is caused by curved spacetime
The first test of Einstein's theory of General Relativity was viewing the area around the eclipsed sun to
a. more accurately measure the diameter of the Sun
b. measure the speed of light
c. see if the stars in that area appeared to change position
d. measure the passage of time on the Sun - ✔✔✔c. see if the stars in that area appeared to change position
A person flies by the Earth in a spaceship at a substantial fraction of the speed of light. An observer on Earth could measure that time on the spaceship
a. is slower than time on Earth
b. is faster than time on Earth
c. is the same as on Earth because the spaceship is not traveling at the speed of light
d. travels in a loop - ✔✔✔a. is slower than time on Earth
In the twin paradox, the twin who stays behind
a. observes that time passes at the same rate for the twin the spaceship
b. observes time standing still for the twin who travels in the spaceship
c. observes time passing more slowly for the twin in the spaceship
d. observes time passing more quickly for the twin in the spaceship - ✔✔✔c. observes time passing more slowly for the twin in the spaceship
An astronaut who fell into a black hole would be stretched because
a. black holes rotate rapidly, dragging and stretching spacetime around them
b. the force of gravity increases quickly over short distances
c. the force of gravity is very strong near a black hole
d. time is slower near the black hole's event horizon - ✔✔✔b. the force of gravity increases quickly over short distances
What are the three basic directly observable structural compounds of the Milky Way? - ✔✔✔The Galactic Disk, The Stellar Halo, The Bulge
If the Sun collapsed into a black hole today, how would it affect the Earth?
, a. it would be dark
b. people, farm animals, and other small things would literally get sucked right off the Earth
c. Earth's orbit would widen
d. Earth's orbit would shrink - ✔✔✔a. it would be dark
The galactic disk of the Milky Way - ✔✔✔Located on the equatorial plane
A flattened distribution of stars and interstellar material within a galaxy
Distinguishes the Milky Way as a spiral galaxy. (Spiral arms: where the density of stars and gas increases, higher concentration of massive blue stars)
The stellar halo of the Milky Way - ✔✔✔Surrounding the disk
old, widely dispersed globular clusters and stars
Spherical shape
lacks star-forming gas
The bulge of the Milky Way - ✔✔✔The central region of a spiral galaxy that is similar in appearance to a small elliptical galaxy. Extend above and below the disk.
Football shaped. Population II stars. High gas and dust content. Supermassive black hole at the center. Very dense stellar population
Explain how black holes are observed. - ✔✔✔Black holes are observed by the large amounts of light (x-rays) emitted from orbiting and infalling material
The formation of the Milky Way's _____ depended on the presence of gas - ✔✔✔disk
Halo objects orbit the center of the Milky Way, - ✔✔✔in random orientations and directions.
The Milky Way's ______ is/are composed of stars (and gas and dust) in randomly oriented objects - ✔✔✔halo and bulge
Consider the rotation curve (velocity vs. radius) graph of a merry-go-round. The velocity
a. declines as radius increases
b. increases as radius increases
c. is relatively constant as radius increases - ✔✔✔d. increases as radius increases
Consider a typical disk galaxy's rotational curve (velocity vs. radius). The velocity
a. increases as radius increases
b. decreases as radius increases
c. is relatively constant as radius increases - ✔✔✔c. is relatively constant as radius increases
The Milky Way's rotational curve provides evidence of dark matter because - ✔✔✔additional, invisible matter is required to keep the rotation speed relatively
constant AND
the rotation curve extends far beyond the Milky Way's disk
The Special Theory of Relativity - ✔✔✔1. All motion is relative: no special frame of reference exists from which an absolute standard of motion can be judged
2. The speed of light is the same for all observers, no matter what their state of motion
Einstein's theory of General Relativity predicts that
a. lengths appear to contract for moving objects
b. stars should collapse into black holes
c. gravity is caused by curved spacetime
d. time appears to slow for moving objects - ✔✔✔c. gravity is caused by curved spacetime
The first test of Einstein's theory of General Relativity was viewing the area around the eclipsed sun to
a. more accurately measure the diameter of the Sun
b. measure the speed of light
c. see if the stars in that area appeared to change position
d. measure the passage of time on the Sun - ✔✔✔c. see if the stars in that area appeared to change position
A person flies by the Earth in a spaceship at a substantial fraction of the speed of light. An observer on Earth could measure that time on the spaceship
a. is slower than time on Earth
b. is faster than time on Earth
c. is the same as on Earth because the spaceship is not traveling at the speed of light
d. travels in a loop - ✔✔✔a. is slower than time on Earth
In the twin paradox, the twin who stays behind
a. observes that time passes at the same rate for the twin the spaceship
b. observes time standing still for the twin who travels in the spaceship
c. observes time passing more slowly for the twin in the spaceship
d. observes time passing more quickly for the twin in the spaceship - ✔✔✔c. observes time passing more slowly for the twin in the spaceship
An astronaut who fell into a black hole would be stretched because
a. black holes rotate rapidly, dragging and stretching spacetime around them
b. the force of gravity increases quickly over short distances
c. the force of gravity is very strong near a black hole
d. time is slower near the black hole's event horizon - ✔✔✔b. the force of gravity increases quickly over short distances
What are the three basic directly observable structural compounds of the Milky Way? - ✔✔✔The Galactic Disk, The Stellar Halo, The Bulge
If the Sun collapsed into a black hole today, how would it affect the Earth?
, a. it would be dark
b. people, farm animals, and other small things would literally get sucked right off the Earth
c. Earth's orbit would widen
d. Earth's orbit would shrink - ✔✔✔a. it would be dark
The galactic disk of the Milky Way - ✔✔✔Located on the equatorial plane
A flattened distribution of stars and interstellar material within a galaxy
Distinguishes the Milky Way as a spiral galaxy. (Spiral arms: where the density of stars and gas increases, higher concentration of massive blue stars)
The stellar halo of the Milky Way - ✔✔✔Surrounding the disk
old, widely dispersed globular clusters and stars
Spherical shape
lacks star-forming gas
The bulge of the Milky Way - ✔✔✔The central region of a spiral galaxy that is similar in appearance to a small elliptical galaxy. Extend above and below the disk.
Football shaped. Population II stars. High gas and dust content. Supermassive black hole at the center. Very dense stellar population
Explain how black holes are observed. - ✔✔✔Black holes are observed by the large amounts of light (x-rays) emitted from orbiting and infalling material
The formation of the Milky Way's _____ depended on the presence of gas - ✔✔✔disk
Halo objects orbit the center of the Milky Way, - ✔✔✔in random orientations and directions.
The Milky Way's ______ is/are composed of stars (and gas and dust) in randomly oriented objects - ✔✔✔halo and bulge
Consider the rotation curve (velocity vs. radius) graph of a merry-go-round. The velocity
a. declines as radius increases
b. increases as radius increases
c. is relatively constant as radius increases - ✔✔✔d. increases as radius increases
Consider a typical disk galaxy's rotational curve (velocity vs. radius). The velocity
a. increases as radius increases
b. decreases as radius increases
c. is relatively constant as radius increases - ✔✔✔c. is relatively constant as radius increases
The Milky Way's rotational curve provides evidence of dark matter because - ✔✔✔additional, invisible matter is required to keep the rotation speed relatively
constant AND
the rotation curve extends far beyond the Milky Way's disk
