CH 29.1 Flashcards
is a round, three dimensional object, the surface of which is the same distance from center in all directions
sphere
is elongated, closed curve with two foci
ellipse
is earth a perfect sphere
no the width is longer than the height
what are some ancient observation that proves earth is a sphere
no matter where you are at an object falls like if it was falling towards the center of a sphere, the shadow of earth on the moon during a lunar eclipse is always curve, we all see different stars
what are two factors that effect gravitational strength??????????
the mass, and the distance
which diameter of earth from pole pole or through the equator
diameter of the equator
what does the magnetic field protect earth from
solar flares, harmful radiation from the sun
the south magnetic pole is located in which hemisphere
north hemisphere
the south magnetic pole is located in which hemisphere
north hemisphere
the north magnetic pole is located in which hemisphere
south hemisphere
what degree is earth axis titled at
11.7 degree
do the magnetic poles reverse
yes they do
what is the large scale reversals called
magnetic reversals
how often do magnetic reversals occur
200,000 years
when was the last magnetic reversal
780,000 years ago
what is the part of the magnetic field deflects harmful radiation from the sun
the magneto sphere
what is the southern lights and the northern lights called
the Aurora borealis (northern lights) Aurora austrails (southern lights
how are the auroras created
electricity charged particles collides with atoms in the atmosphere and emit light
in which month is earth closest to the sun
in which month is earth closest to the sun
January(147 million km away)
during which month are we furthest from the sun
july( 152 million km away)
an area 15 degree wide in which the time is the same
time zone
is the spinning of Earth on its axis
rotation
is the motion of Earth in an elliptical orbit around the sun
revolution
defined as the plane of Earth’s orbit around the sun
ecliptic
occurs when Earth’s rotational axis is tilted directly toward the sun or away from the sun
solstice
Earth’s rotational axis is perpendicular to a line drawn from the center of Earth to the center of the sun
equinox
who devised a method of timekeeping around 3000 B.C.
the Babylonians
what was the symbol for degree taken from
it was the symbol for the sun
how many degrees does earth spin in one day
360 degrees
how many hours does it take the earth to make one full rotation
24 hours
what direction does the sun rise
west
what direction does the earth set
east
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 cities
how many time zone are there in the united states
6 time zones
what are the names of the time zones
pacific time, mountain time, eastern time, central time, Atlantic time, Hawaiian time
what is a solar day
is the movement of the sun from noon one day until noon the next day
what is a sidereal day
where we look at a specific start and make a full rotation to the same star the next day
what are the two main reasons for seasons
the title of the earth and the revolution
which two seasons have a solstice
which month is the summer solstice
which month is the winter solstice
which two seasons are equinox
which month is the spring equinox
which month is fall equinox
when is the longest day of the year
when in the shortest day of the year
when are the days almost 12 hours of day and 12 hours of night
how many degrees does the earth spin in one hour
15 degrees
how many time zones are there in the world
24 zones
what direction do you move to add hours to the time
east
what direction do you move to subtract hours to the time
west
