Questions from the midterm Flashcards
On the 1-to-10-billion scale, about how far is it to the nearest stars besides the Sun?
a) 4 kilometers
b) 400 kilometers
c) 1,000 kilometers
d) 4,400 kilometers
e) 10,000 kilometers
d (about 4,400 km)
The distribution of the mass of the Milky Way Galaxy is determined by
a) Counting the number of stars.
b) Determining the amount of gas and dust.
c) Studying how stars are distributed in the Milky Way.
d) Studying the rotation of the galaxy.
e) Weighing various parts of the Milky Way.
d (studying the rotation of the galaxy)
Why were ancient peoples unable to detect stellar parallax?
a) They did not look for it.
b) They could not see distant stars.
c) They did not have the ability to measure very small angles.
d) They did not observe for long enough periods of time.
e) They did detect it, but they rejected the observations.
c (they did not have the ability to measure very small angles)
We can’t detect stellar parallax with naked-eye observations. Which of the following would make parallax easier to observe?
a) Increasing the size of Earth’s orbit
b) Speeding up Earth’s rotational motion
c) Slowing down Earth’s rotational motion
d) Speeding up the precession of Earth’s axis
e) Getting away from streetlights
a (increasing the size of earth’s orbit)
Which of the following statements about parallax is not true?
a) You can demonstrate parallax simply by holding up a finger and looking at it alternately from your left and right eyes.
b) The existence of stellar parallax is direct proof that Earth orbits the Sun.
c) Measurement of stellar parallax allows us to determine distances to nearby stars.
d) The technique of stellar parallax was used by Hubble to determine that the Andromeda Galaxy (M 31) is about 2 million light-years away.
e) Ancient astronomers were unable to measure parallax and used the absence of observed parallax as an argument in favor of an Earth-centered universe.
d (the technique of stellar parallax was used by Hubble to determine that the Andromeda Galaxy M31 is about 2 million light years away
An angle of 1 arcsecond is
a) About the width of your fist held at arm’s length.
b) About the width of a finger held at arm’s length.
c) less than the thickness of a human hair held at arm’s length.
d) Slightly more than the width of a basketball held at arm’s length.
c (less than the thickness of a human hair held at arm’s length)
The controversial book of this famous person, published in 1543 (the year of his death), suggested that Earth and other planets orbit the Sun.
a) Tycho Brahe
b) Copernicus
c) Kepler
d) Galileo
e) Ptolemy
b (Copernicus)
In order to tell time at night, the ancient Egyptians of 3000 B.C. used
a) Sundials, with light provided by the Moon.
b) Water clocks, measuring the flow of water through an opening.
c) Hourglasses, measuring the flow of sand through an opening.
d) Moon clocks, which measured time based on the Moon’s position relative to the stars.
e) Star clocks, which measured time based on the positions of stars at particular times of night and particular times of year.
e (star clocks, which measured time based on the positions of stars at particular times of night and particular times of year)
The tides on Earth are an example of
a) Newton’s first law of motion.
b) Newton’s second law of motion.
c) Newton’s third law of motion.
d) The universal law of gravitation.
e) None of the above
d (the universal law of gravitation)
In which of the following cases would you feel weightless?
a) While walking on the Moon
b) While falling from an airplane with your parachute open
c) While traveling through space in an accelerating rocket
d) While falling from a roof
e) None of the above
d (while falling from a roof)
The ultimate source of energy that powers the Sun is
a) Chemical potential energy of hydrogen burning into helium.
b) Mass energy of hydrogen fusing into helium.
c) Gravitational potential energy of the contraction of the gas cloud that formed the Sun.
d) Kinetic energy of the orbital motion of the Sun.
e) Thermal energy of the hydrogen atoms in the Sun.
b (mass energy of hydrogen fusing into helium)
