Page 206 - NAVAL SCIENCE 3 TEXTBOOK

212 NAVAL SKILLS

6. A. How did telling time by ship's bell originate? CRITICAL THINK ING
B. \·Vhat is the maximum number of bells struck?
I. "Vhy is an accurate timepiece of great importance in celestial
7. What is the basic relationship between longitude (arc) and navigation as sea?
time?
2. \Vhat are the advantages of keeping zone time as opposed to
8. Why does the length of each solar day vary slightly? a single standardized time throughout the world? Would you
9. \·Vhat is mean solar time? prefer to keep time according to your local zone time. or keep
a standard time such as Greenwich Mean Time? Justi~r your
10. A. How ha\'e people made time setting and time keeping
answer.
more practical?
B. How many degrees of longitude are in each standard time
zone? VOCABULARY
II . How is each time zone identified?
jet lag standard time
12. How do the dates on each side of the International Date Line chronometer local mean time
difter? solar time zone time
13. What is daylight savings time? mean time zone description (ZD)
apparent time Greenwich Mean Time (GMT)
14. \Vhat are the four standard time zones in the continental
United States' IdentifY each with its alphabetical suffix and equation of time universal coordinated time (UTC)
numerical ZO. almanac date/time group
rotation (of Earth) daylight savings time
I S. Convert the following zone times to Greenwich Mean Time:
revolution (of Earth) mean Sun
A. 1200 at San Francisco (ZD = +8)
B. 1700 at Norfolk (ZD = +5)
C. 0600 at Rome, Italy (ZD = - I)
16. Convert the following Greenwich ~'[ean Times to zone time at
the locations in the previous question:
A. GMT 0800
B. GMT 1600
17. What are the date/time groups for the following:
A. 0835 local time in Norfolk, Virginia, on 23 March 2010'
B. 7:30 P.'I. in San Diego, California, on 17 Mal' 2010'