Transcript Gravity- I`m Attracted to You

GravityI’m Attracted to You
Earth Space
Gravity
force of attraction that exists between
all matter in the universe.
► The
 Key word is matter
 Matter is the stuff you are and everything else is
made of
► It
takes a lot of mass for the gravity to be
noticeable.
 Like planetary mass
Law of Gravity
► The
force of attraction between any two
objects depends on their masses and the
distances between them.
 The bigger the object, the more gravity it has
 The closer an object is to something the
stronger the pull.
Mass
is how much matter is in something.
► It is measured using grams and kilograms
► It is NOT the same as weight
► Mass
Distance
► Gravity’s
force depends on how close the
object is to something.
► As an object gets further away, the force of
gravity on that object decreases
► Inverse square law
 As the distance increases the gravity decreases
exponentially
► Class
demonstration
1
Gravitational force =
Distance squared
G force =
1
d2
Weight, Mass, and Gravity
►Weight
and Mass are not
the same thing!!!
► The
are related though
► Weight is your mass being pulled down by
gravity
► Gravity on earth pulls us down at 9.8 m/s2
Weight, Mass, and Gravity
Mass
► How much matter you
are made of
► Does not change
depending location
► It is the same if you
are on earth or in
space or on the moon
Weight
► The relationship
between mass and
gravity
► Changes depending on
location
► Is different on earth
and the moon and
space
► In
the absence of air resistance, all things
will fall toward the earth at the same
velocity
► Weight = mass x free-fall acceleration
► w= m g
Find Your Mass
► We
can find out how much mass we have by using
the previous formula
►W
= mg
► Weight is in Newtons, so convert your lbs to N.
 Multiply lbs times 4.448
► Then
divide by gravity
Gravity on Earth
► Gravity
pulls us down toward the center of
the earth.
► At different parts of the earth there is more
matter between the surface and the center.
► The Poles are flatter and the equator bulges
 The bulge means there is more gravity at the
equator
 People weigh more at the equator than the
poles.
Gravity & the Moon


Newton observed the Moon’s motion and
realized that its direction changes because of
the gravitational attraction of Earth
 The Moon is constantly falling toward Earth
 If no gravity, the Moon would continue to
move in a straight line and would not orbit
Earth
The same is true of the planets and their
moons, stars, and all orbiting bodies
throughout the universe.