Day and Night

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Day and Night SOL 3.8
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Objects and events on Earth can Change.
Some of these changes are slow. Some of these
changes are fast.
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Some of the changes on Earth occur in patterns
and happen over and over again.
When these changes occur over and over again, we
call them cycles.
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One of the cycles on Earth that we can observe
and describe is the cycle of Day and Night.
First its day, then its nightthen its day,
then its night.then its day again, then its
night..
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The sequence of day and night is caused by the
rotation of the Earth on its axis.
axis
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The axis is an imaginary line (it is not really
there). It takes the Earth 24 hours to
complete one rotation on its axis. 24 hours 1
day on Earth.
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Day and Night are caused by the Earths rotation
on its axis.
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As the Earth rotates (turns), the side of the
Earth toward the sun has day while
the part not facing the sun has night.
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If its daytime on our side of the world,
its nighttime on the opposite side of the
world.
When we go from day to night to day to nightits
called a cycle.
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The Earth completes 1 rotation on its axis every 2
4 hours.
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Thats why we begin a new day every 24 hours!
Every time the Earth begins a new rotation, we
are beginning a new day.
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Lets see how well you learned about the cycle of
day and night
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1. Why is it nighttime on one side of the Earth
while it is daytime on the other side?

• The suns light is shining on the side where it
  is nighttime.
• The suns light is shining on the side where it
  is daytime.
• The moon is on that side of the Earth.

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• How long does it take the Earth to turn (rotate)?

• 12 ½ hours
• 24 hours
• 1 year

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• What is the Earths axis?

a)an imaginary line b)the center of the
earth c) a real line going through the earth
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End of show!