|
Mystery
Class # ____ |
Sunrise
in UT/GMT
and Date |
Step
#1
Fill in the UT/GMT sunrise time and date for the Mystery Class.
This is the time it is at Greenwich, England when the sun rises
at the mystery location.
Put
answer in Box A.
|
BOX
A
_______time______date
|
Step
#2
Fill in the time that the sun rises at Greenwich, England on
March 20, the spring equinox. This year that sunrise time is
06:02 A.M.
Put
answer in Box B.
|
BOX
B
06:02 A.M. (3/20) |
Step
#3
Figure out how many hours and minutes there are between the
time in Box A and the time in Box B. Put answer in Box C. This
is the difference in time between sunrise at Greenwich and sunrise
at the mystery location.
(CAUTION!!! This may not
be a simple subtraction or addition equation. Remember that
hours and minutes are not in decimal form. Be sure to think
about your answer!)
Put
answer in Box C.
|
BOX
C
_______hours______minutes
|
Step
#4
For the next step you'll need to convert hours to minutes. Multiply
each hour in Box C by 60, then add the remaining minutes from
Box C.
Put
answer in Box D.
|
BOX
D
________minutes |
Step
#5
Almost done! You now know how many minutes the earth spins between
the time the sun rises at the Mystery Class location and the
time it rises at Greenwich. Since the earth spins 1 degree longitude
every 4 minutes, you must next divide by 4 to get the number
of approximate longitude degrees away from Greenwich. Divide
the number of minutes given in Box D by 4.
Put answer in Box E.
|
BOX
E
________degrees |
Step
#6: Eastern or Western Hemisphere?
To determine the site's longitude you need to know if it is
in the Eastern or Western Hemisphere (i.e east or west of Greenwich,
which is 0 degrees).
- If
the sunrise time in Box A is later than the
sunrise time in Box B, the Mystery Class is west of Greenwich
(Western Hemisphere).
- If
the sunrise time in Box A is earlier than the sunrise
time in Box B, the Mystery Class is east of Greenwich (Eastern
Hemisphere).
|
BOX
F
East or West? |