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Introduction to Gravity for Children: Gravity, Weight, and Mass for Kids - FreeSchool

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    Any time you drop something,
    it falls down.
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    But - why? Why do you come back down,
    no matter how hard you jump on that trampoline?
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    When you throw a ball, why does it fall
    to the ground instead of flying off into space?
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    The answer is gravity, but it does
    a lot more than pulling things down.
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    Gravity is an invisible force that
    pulls objects towards each other.
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    In most cases,
    when we say "gravity"
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    we are talking about the earth's gravity,
    but anything that has mass has gravity, too.
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    Yes, even you have gravity! 
    Of course, you don't have very much gravity.
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    The more mass something has,
    the more gravitational force it has.
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    Compared to the gravity
    of the earth,
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    any gravitational force that
    you have is too weak to notice.
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    Mass is not the same
    as weight.
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    Mass is a measure of the matter in an object, 
    and does not change no matter where you go.
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    On the other hand, weight measures the pull 
    of gravity on an object, and this can change.
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    Most places on earth have roughly 
    the same amount of gravity,
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    but if you were to leave earth,
    the pull of its gravity
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    would weaken
    the farther away you went,
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    until eventually
    you would experience zero-g.
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    This is because gravity
    gets weaker with distance.
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    There is still gravity in space, because 
    everything that exists exerts gravitational force,
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    but the gravitational pull
    from something like a person
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    or even a spaceship is so small
    it feels as though you have no weight at all.
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    If you were to land on another
    planet or celestial body,
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    the pull of gravity would be
    different depending on its mass,
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    and you would not weigh
    the same as you did on earth.
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    On the moon, for example,
    gravity is only about 17% of earth's.
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    This is because the moon
    is much less massive than the earth.
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    A person who weighs 100 pounds
    or 45 kilograms on earth
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    would weigh only 17 pounds
    or 7 and a half kilograms on the moon.
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    On Mars, the same person
    would weigh 38 pounds or 17 kilograms.
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    On Jupiter, they would weigh
    253 pounds or 106 kilograms.
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    Gravity is the weakest of the four 
    fundamental forces of the universe,
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    and only gets weaker with distance,
    but it is very important for life on Earth.
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    It is the force that holds us down
    to the surface of the planet.
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    Gravity makes things fall down,
    and gives things weight.
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    It is what holds the Earth together, and keeps
    the air we breathe from spinning off into space.
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    Gravity also holds
    our solar system together.
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    The earth's gravity holds the moon
    in orbit around the Earth.
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    The sun's gravity holds the Earth and all
    the other planets in orbit around the sun.
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    On a larger scale, even the Milky Way 
    galaxy is held together by gravity.
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    Scientists believe that a supermassive
    black hole sits at the center of the Milky Way,
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    with its gravity holding all the gas,
    dust, stars and systems in place around it.
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    Black holes have so much mass
    in such a small space
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    that their gravitational pull
    is very strong.
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    They generate such strong gravity
    that not even light can escape from them,
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    and that's why
    they look black!
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    So you see, while gravity 
    may be an invisible force,
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    it has a very visible
    impact on our lives.
Title:
Introduction to Gravity for Children: Gravity, Weight, and Mass for Kids - FreeSchool
Description:

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Video Language:
English
Duration:
04:40

English subtitles

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