Chapter #20 Solutions - Physical Science with Modern Applications - Melvin Merken - 5th Edition

 

1. How do we know the chemical composition of stars? Get solution

2. (a) What information does a red shift in its spectrum yield about a star? (b) a blue shift? Get solution

3. Why are optical astronomers for the most part limited to nighttime observation, whereas radio astronomers can observe during the day? Get solution

4. Astronomically, in what way have our senses been expanded in recent years? Get solution

5. Which distance is greater, a light-year or an astronomical unit? Explain. Get solution

6. Why is bigger better for astronomical telescopes? Get solution

7. If the Andromeda spiral galaxy is approaching us at a velocity of 290 km/s, how long will it take to reach us if the distance is 225 × 106 ly? Get solution

8. A star is 45 ly away. Traveling at a speed of 100,000 mph, how long would it take to reach this star? Get solution

9. Indicate the close relationship of other physical sciences to astronomy. Get solution

10. How are the positions of celestial objects specified? Get solution

11. The parallax of a star is 0.001". How far away is it in ly? Get solution

12. Constellations and galaxies are both groups of stars. In what ways do they differ? Get solution

13. Why are the constellations of the winter sky different from those of summer? Get solution

14. When we look up at the stars, we are looking back in history. Explain. Get solution

15. Why is the Hertzsprung-Russell diagram considered by some astronomers to be the most important diagram in astronomy? Get solution

16. Distinguish between pulsars and pulsating stars. Get solution

17. What does the sequence O, B, A, F, G, K, M represent? Get solution

18. What is stellar evolution? Get solution

19. How did the “guest star” of AD 1054 become associated with the discovery of pulsars? Get solution

20. What are some differences between a nova and a supernova? Get solution

21. What is a black hole? Get solution

22. Describe the possible final stages in the life cycle of a star. Get solution

23. What role has the radio telescope played in the recent revolution in astronomy? Get solution

24. What is the distinction between a nebula and a galaxy? Get solution

25. Galaxies have been referred to as the structural units of the universe. Explain. Get solution

26. How have the 21-cm radio waves emitted by neutral hydrogen extended our knowledge of the universe? Get solution

27. Why is the name “Milky Way” appropriate for our galaxy? Get solution

28. What is the difference between an open and a globular star cluster? Get solution

29. What is Hubble’s law and what does it mean? Get solution

30. What is meant by “the expansion of the universe”? Get solution

31. What is a quasar? Get solution

32. Explain why astronomers of today can actually observe galaxies as they were billions of years ago. Get solution

33. Multiple ChoiceA. The average distance from the earth to the sun is(a) a light-year.(b) an astronomical unit.(c) an angstrom unit.(d) a parsec.B. A nova is(a) a star that suddenly increases in brightness.(b) a pulsar.(c) a quasar.(d) a receding galaxy.C. The remnant of the big bang is also known as(a) a neutron star.(b) a black hole.(c) 3K background radiation.(d) the interstellar medium.D. The energy of a main sequence star comes from(a) gravitation.(b) nuclear fission.(c) nuclear fusion.(d) helium burning.E. A Doppler red shift for a galaxy indicates that it is(a) approaching.(b) receding.(c) slowing down.(d) speeding up. Get solution