Chapter 1: our place in the universe

1) What is the concept of galactic recycling?

2) What is the Sun mainly made of?

3) Rank the following: size of a typical planet, 1 light-second, 1 AU, size of

a typical star

4) Rank the following: size of a typical galaxy, size of Pluto's orbit, distance

to the nearest star (other than our Sun), 1 light-year

5) How would you best describe the Milky Way Galaxy? What is its shape,

what is the size of its diameter and how many stars does it contain

approximately?

6) On the scale of the cosmic calendar, in which the history of the universe

is compressed to 1 year:

- How long has human civilization (i.e., since ancient Egypt) existed?

- When did the dinosaurs become extinct?

- When did Kepler and Galileo first discover that we live on a planet in a

solar system?

7) From the fact that virtually every galaxy is moving away from us and

more distant galaxies are moving away from us at a faster rate than closer

ones, what do we conclude?

8) Rank the following 4 items by how long it takes for light to reach us from

these objects, from shortest to longest: Sun, Pluto, the Andromeda Galaxy,

center of the Milky Way

9) You have taken a picture of a galaxy 1 billion light years away. What can

you say about the age of the galaxy?

10) According to current scientific estimates, when did the Big Bang occur?

11) An astronomical unit (AU) is ________.

Chapter 2: discovering the universe

12) When we look into the band of light in our sky that we call the Milky

Way, can we see distant galaxies? Why or why not?

13) What makes the North Star, Polaris, special?

14) Why is it summer in the Northern Hemisphere when it is winter in the

Southern Hemisphere?

15) What conditions are required for a solar eclipse (hint: phase of the moon

and nodes of the Moon’s orbit)?

16) What conditions are required for a lunar eclipse (hint: phase of the

moon and nodes of the Moon’s orbit)?

17) What causes the apparent retrograde motion of the planets?

18) If the Earth's rotation axis was tilted by 45 degrees instead of 23.5

degrees, how would that affect the climate of the Earth? Would the seasons

be more or less extreme? Why?

19) What do astronomers mean by a constellation?

20) What is the celestial sphere?

Chapter 3: the science of astronomy

21) What does Kepler’s third law say? If an asteroid has an orbital period of

8 years,what is the average distance of the asteroid from the Sun in

astronomical units?

22) What does Kepler’s second law say? How would you apply this

knowledge to our own Solar System? Choose two (or more!) planets in the

Solar System and explain.

23) When Copernicus first created his Sun-centered model of the universe, it

did not lead to substantially better predictions of planetary positions than the

Ptolemaic model. Why not? What was the great contribution of Nicholas

Copernicus to Astronomy nevertheless?

24) How did Galileo Galilei solidify the Copernican Revolution? Which

obstacles was he able to overcome to do so?

Chapter 4: motion, energy, gravity

25) What do Newton’s three laws of motion say?

26) If your mass is 60 kg on Earth, what would your mass be on the Moon?

27) Suppose an object is moving in a straight line at 50 mi/hr. According to

Newton's first law of motion, what will happen if there is no external force

acting on the object?

28) Changing the orbit of a spacecraft by firing thrusters is an example of

which Newton’s law of motion?

29) What quantities does angular momentum depend upon?

30) What does the amount of gravitational potential energy which is

released as an object falls depend on?

31) What does kinetic energy of a moving object depend on?

32) What is radiative energy?

33) What is the difference between thermal energy and temperature?

34) What does the law of conservation of energy say? Give an example of

conservation of energy in a closed system (that means no external force).

35) The force of gravity is an inverse square law. What will happen to the

gravitational force between two masses, if you triple the distance between

them?

36) According to the universal law of gravitation, if you double the masses

of both attracting objects,then what will happen to the gravitational force

between them?

Chapter 5: light

37) What is the frequency of a wave?

38) What is the wavelength of a wave?

39) Rank the following, from lowest energy to highest energy:

infrared, visible light, ultraviolet, X-rays, gamma rays, radio

40) Suppose you know the frequency of a photon and the speed of light.

What else can you determine about the photon?

41) In what ways do light and matter interact?

42) How can an electron in an atom lose energy to go from a higher energy

level to a lower energy level? How does it go from a lower energy level to a

higher energy level? What stands for the frequency (therefore the energy

too) of the photon involved in this process?

43) Write the appropriate interaction between light and matter in each

example (absorption, transmission, emission, reflection or scattering):

- Blue light hitting a red sweatshirt

- Cell phone signals passing through walls

- Light coming from a firefly

- Red light hitting a red car

- Radio waves passing through mountains and reaching your car

- Ultraviolet rays causing sunburn

- The light released from a star

- The fact that we see the Moon and some planets

44) How is thermal radiation defined as? Suppose you see two stars: a blue

star and a red star. What can you conclude about the two stars?

45) What do we call redshift?

Various multiple choice questions

1) Suppose we imagine the Sun to be about the size of a grapefruit. How big

an area would the orbits of the nine planets of the Solar System cover? A) the size of a typical dorm room

B) the size of a typical campus building

C) the size of a typical campus

D) the size of a small city

E) the size of a western state (e.g.,Colorado)

2) Which of the following statements does not use the term light-year in an

appropriate way? A) It's about 4 light-years from here to Alpha Centauri.

B) It will take me light-years to complete this homework assignment.

C) A light-year is about 10 trillion kilometers.

D) It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year.

E) The Milky Way Galaxy is about 100,000 light-years in diameter.

3) Suppose we look at a photograph of many galaxies. Assuming that all

galaxies formed at the same time after the Big Bang, which galaxy appears

to us as the youngest? A) The galaxy that is furthest from us.

B) The galaxy that is closest to us.

C) The galaxy that appears largest to us.

D) The galaxy that appears bluest to us.

4) When are eclipse seasons? A) in the spring and fall

B) in the summer and winter

C) when the nodes of the Moon's orbit are nearly aligned with the Sun

D) when Earth, the Sun, and the Moon are exactly aligned for an eclipse

E) during an eclipse

5) Which of the following statements about constellations is false? A) There are only 88 official constellations.

B) Some constellations can be seen from both the Northern and Southern hemispheres.

C) Some constellations can be seen in both the winter and summer.

D) It is possible to see all the constellations from Earth's equator.

E) Most constellations will be unrecognizable hundreds of years from now

6) The ancient Greeks get a lot of attention for their contributions to science

because ________. A) they were the first people known to try to explain nature with models based on reason and

mathematics, without resort to the supernatural

B) the books of every other culture were lost in the destruction of the library of Alexandria

C) they were the first people to realize that Earth is a planet orbiting the Sun

D) they were the only ancient culture that kept written records of their astronomical observations

7) According to what we now know from Newton's laws, which of the

following best explains why Kepler's second law is true? A) A planet's total orbital energy must be conserved as it moves around its orbit.

B) Orbits must be elliptical in shape.

C) Gravity is an inverse cube law.

D) This effect happens because of the influence of other planets on a particular planet's orbit.

8) The mass of Jupiter can be calculated by A) measuring the orbital period and distance of Jupiter's orbit around the Sun.

B) measuring the orbital period and distance of one of Jupiter's moons.

C) measuring the orbital speed of one of Jupiter's moons.

D) knowing the Sun's mass and measuring how Jupiter's speed changes during its elliptical orbit

around the Sun.

E) knowing the Sun's mass and measuring the average distance of Jupiter from the Sun.

9) Considering Einstein's famous equation, E = mc2, which of the following

statements is true? A) Mass can be turned into energy, but energy cannot be turned back into mass.

B) It takes a large amount of mass to produce a small amount of energy.

C) A small amount of mass can be turned into a large amount of energy.

D) You can make mass into energy if you can accelerate the mass to the speed of light.

10) We are measuring the spectra of two hydrogen gas clouds. The

laboratory frame wavelength of one hydrogen line is 656.2 nm. Cloud A's

emission line wavelength is 660.1 nm and Cloud B's emission line

wavelength is 670.1 nm. What can we conclude about these clouds? A) They are both approaching us, and Cloud B is approaching faster than Cloud A.

B) They are both receding from us, and Cloud B is receding faster than Cloud A.

C) They are both approaching us, and Cloud A is approaching faster than Cloud B.

D) They are both receding from us, and Cloud A is receding faster than Cloud B.

11) One star is emitting primarily visible light and another star is emitting

primarily infrared light. Which star is hotter? A) The star emitting infrared light.

B) The temperature also depends on the radius of the star, so one can't decide based on the

information provided.

C) The star emitting visible light.

D) Both stars are the same temperature.