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Hands On Mineral Identification helps you to identify over 14,500 minerals! By M. Darby Dyar, Ph.D. See our DVD collection.

Can you explain gravity? How come two balls hit the ground at the same time? If you hang a one liter bag of formula from a six foot pole and another one liter bag of formula from a three foot pole. Will the bags empty at the same rate ??

Have you ever played with magnets? The Earth acts like a giant magnet, pulling everything near it to the ground. It pulls on bigger objects more than little objects. But it's harder to pull larger objects down than little ones. That's why they all fall at the same speed to the ground.

Have you ever jumped off a swing? Gravity pulls you down at the same speed as a ball that you throw into the air! It doesn't matter how big you are! Isaac Newton was one of the first scientists to work with gravity.

Things that are farther away aren't pulled on as much, so they fall slower than objects near the ground.


Submitted by Danielle (California, USA), Matthew (Ontario, Canada), Adrienne (Michigan, USA), G.S.(New Jersey, USA), K(Chennai, India)
(May 18, 1999)



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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA