Practice Questions

1. What is the total number of galaxies in the observable universe?

2. How are speed and velocity different?

3. Rank the following objects from the smallest to the largest: Earth, Sun, Local Group, Virgo cluster, Pluto, Halley's Comet, Coma Supercluster, The Large Magellan Cloud, Milky Way Galaxy, Moon, Jupiter.

4. True or False: The orbits of nearly all large objects in the solar system, the planets and large moons, go from East to West.

5. True or False: The rotation of nearly all large objects in the solar system, the Sun, the planets, and large moons go from West to East.

6. What is the apparent retrograde motion of a planet, like Mars or Saturn?

7. How did the ancient Greeks measure the radius of the earth?

8. One evening you see the moon starts to rise from the eastern horizon as the Sun is beginning to set. The moon will appear as _________________.

9. One evening at 7 PM you see a crescent Moon setting shortly after sunset. Is it a waxing or waning crescent?

10. How did the observation of the four moons of Jupiter by Galileo invalidate the geocentric system?

11. Around which part of a comet's orbit does it have "hair"?

12. Roughly, what's the size of the Milky Way galaxy?

13. What type of galaxy is the MW?

14. What did Ptolemy propose to explain the retrograde motion of a planet?

15. How do we know the Crab nebula is the remnant of a supernova explosion?

16. Where is the center of mass of a hammer, roughly? Close to the tip of the handle or the hammerhead?

17. True or False: Kepler's First Law says planets go around the Sun in elliptical orbits and the Sun is at the center of the orbit.

18. What does Kepler's Third Law say?

19. What does Kepler's Third Law imply? A planet whose orbit is far away from the Sun will have higher or lower average velocity than a planet whose orbit is close to the Sun?

20. Order the eight planets according to their distances from the Sun.

21. Kepler's Second Law implies that when a planet is closer to the Sun in its orbit, it is moving faster or slower than when it's far away from the Sun?

22. What trajectory does the center of mass of an object follow as it is thrown into the air at some angle (between 0 and 90°)?

23. What does Hubble's Law state?

24. True or False: According to Newton's First Law, when a spaceship runs out of fuel, it will gradually come to a stop.

25. Since 2006, Pluto has been classijied as ___________________.

26. Roughly how big is the Sun, a Jupiter-like planet, an Earth-like planet, a typical dwarf planet, a typical asteroid, and a typical comet?

27. The longest day in a year on Earth happens on: Spring Equinox, Summer Solstice, Fall Equinox, or Winter Solstice?