Chapter 5 - Section 5.6 - Modeling Harmonic Motion - 5.6 Exercises - Page 460: 64

1. new moon 2. waxing crescent moon 3. first quarter moon 4. waxing gibbous moon 5. full moon 6. waning gibbous moon 7. third quarter moon 8. waning crescent moon 9. new moon The tides and howling wolves are in phase with the lunar cycle. Seasons and day/night are out of phase with the lunar cycle.

There are nine phases of the moon in the illustration. Note that the first phase and the last phase are the same. We can describe the phases as follows: 1. new moon 2. waxing crescent moon 3. first quarter moon 4. waxing gibbous moon 5. full moon 6. waning gibbous moon 7. third quarter moon 8. waning crescent moon 9. new moon There are some events on the earth that follow a monthly cycle and are in phase with the lunar cycle. These events on earth have some kind of connection with the moon. The tides are influenced by the gravitational pull from the moon, so tides will go through a cycle where high tide will occur at different times during the day depending on the location of the moon. This cycle is in phase with the lunar cycle. The howl of wolves when they howl at the full moon will follow a periodic cycle that is in phase with the lunar cycle. There are many events on earth that are periodic but out of phase with the lunar cycle. These events would not be influenced by the moon or the position of the moon. For example, the cycle of seasons is periodic but this depends on the earth's position on its orbit around the sun. The cycle of day and night is periodic but it does not depend on the moon. The alternation of day and night depends on the earth's rotation about its own axis and is out of phase with the lunar cycle.