29.2 Flashcards
time zone
is an area 15 degrees wide in time is the same
rotation
the spinning of earths axis
revolution
is the motion of earth in an elliptical orbit around the sun
eliptic
is defined as the plane of earths annual revolution
solstice
occurs when earth’s rational axis is tilted directly toward the sun or away fro the sun
equinox
earth’s rotational axis is perpendicular toward a line drawn from the center of earth to the center of the sun
Who devised a method of timekeeping around 3000 B.C.?
Babylonians
What was the symbol for degree taken from?
The Babylonian symbol for the sun
How many degrees does the earth spin in one day?
360 degrees
How many hours does it take the earth to make one full rotation?
24 hours
How many degrees does the earth spin in one hour?
15 degrees
What direction does the sun rise?
East
What direction does the sun set?
West
True or false. All time zones are the exact same size?
False, they are modified to fit around cities, states, and country borders, and other key sites.
How many time zones are there in the world?
24 time zones
Which direction do you move to add hours to the time?
East
Which direction do you move to subtract hours from the time?
west
Which direction do you move to subtract hours from the time?
6 times zones
What are the names of the time zones?
Mountain time zone Eastern time zone Pacific time zone Alaskan time zone Central time zone Hawaiian time zone
What is a solar day?
The earth’s rotation from the sun in the sky from noon one day to noon the next day.
What is a sidereal day?
When a certain star rises above the horizon until that same star rises again
What are the two main reasons for seasons?
The axis tilt and how close earth is to the sun
Which 2 seasons have a solstice?
Summer and Winter
Which month is the summer solstice?
June
Which month is the winter solstice?
december
Which two seasons are equinoxes?
spring and fall
Which month is the spring equinox?
march
Which month is the fall equinox?
september
Which month is the fall equinox?
during the summer solstice
When is the shortest day of the year?
during the winter solstice
When are the days almost 12 hours of day and 12 hours of night?
during the spring equinox and during the fall equinox
