Download Gravity*s Role on Earth

GRAVITY’S ROLE ON EARTH
I can explain gravity’s affect on
orbital motion.
WHAT WAS GALILEO GALILEI’S THEORY?
oGalileo said that if he dropped two balls from the
Leaning Tower of Pisa, they would hit the ground at the
same time.
oHe was right! That led him the to law of freely falling
bodies.
oThere is no evidence that he actually did it, but he was
the first scientist to use the results from experiments for
evidence for a scientific theory.
WHAT IS EXACTLY GRAVITY???
oGravity is a force of attraction between two
objects.
oAll objects with mass have gravity.
oGravity acts like a magnet - pulling objects
together. What causes gravity is not really known.
WHAT WOULD HAPPEN WITH GRAVITY
IF YOU WERE ON THE MOON?
oApollo 11- http://www.youtube.com/watch?v=5MpwArxmbns
oThat was kind of like dropping a piece of paper and feather.
oThe moon is 1/4 the size of Earth, so the moon's gravity is much
less than the earth's gravity, 83.3% (or 5/6) less to be exact.
oIf you were 100 pounds on the earth, you would be 16.6 pounds
on the moon.
GRAVITY’S EFFECTS ON HUMANS…
oGravity is not just a force, it’s also a signal that tells
the body how to act.
oFor one thing, it tells muscles and bones how strong
they must be.
oMuscle mass can vanish at a rate as high as 5% a
week.
oBlood also feels gravity
HOW DOES IT EFFECT THE PLANETS AND
MOVING?
oGravity is a very important force. Every object in space
exerts a gravitational pull on every other, and so gravity
influences the paths taken by everything traveling through
space.
oIt is the glue that holds together entire galaxies.
oIt keeps planets in orbit.
o It makes it possible to use human-made satellites and to
go to and return from the Moon.
SITES:
HTTP://LIBRARY.THINKQUEST.ORG/29033/HISTORY/GA
LILEO.HTM
HTTP://WWW.MOONCONNECTION.COM/MOON_GRAVIT
Y.PHTML
HTTP://WWW.QRG.NORTHWESTERN.EDU/PROJECTS/VSS
/DOCS/SPACE-ENVIRONMENT/ZOOM-GRAV.HTML