Lightening Video - Electric Skies
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I. Below are the stages in the formation and execution of a lightening
strike. (They are already in order.)
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Water vapor rises from the Earth and condenses to form clouds
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Clouds rise to an elevation that is VERY cold (below 0 degrees Celsius/freezing);
that causes ice crystals and ice balls to form
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The ice crystals and ice balls rub and cause charges (positive and negative)
to separate; negative electrons builds up on the bigger ice balls while
the smaller ice crystals loose electrons.
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The positive charge within the cloud rises.
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A spark occurs within the cloud.
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A step leader rushes from the cloud and toward the ground, but does not
quite reach the ground; as the negative step leader gets near the ground,
it exerts an electric force on the ground (i.e., it pulls on the charge
in the Earth).
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Objects that are higher (trees, telephone poles, etc.) launch a positive
streamer of charge toward the step leader.
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The positive streamer from the ground and the negative step leader from
the cloud meet.
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The step leader drains to the Earth and negative charge moves up from the
ground to the cloud.
II. What are some ways to be safe during a lightening storm?
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squat down w/ your feet together
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get in a low area or ditch
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get in a car that is not moving
III. List some dangerous activities during a lightening storm.
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activities in an open area such as golf
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using plumbing such as using the shower, toilet, or sink
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swimming or boating
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talking on the phone
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standing/playing in high areas like on hills
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standing next to any high objects
IV. Why is it dangerous to stand next to a tree during a lightening
storm?
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lightening can jump from the tree to you!!
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as the sap is suddenly heated, the bark can explode and hit you like
lots of bullets (shrapnel)
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falling branches may strike you
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