Download Universal Law of Gravity Notes


Mass- the amount
of atoms inside an
object
◦ Mass does not
change!

Weight- the pull of
gravity on the mass
of an object
◦ Weight changes
depending on the
gravity of a planet

Gravity: The attraction between 2 objects
◦ First described by Sir Isaac Newton
◦ Why is gravity important?
 It’s the force that keeps us on earth
 Keeps the planets from crashing into the sun

All objects with mass have
gravity
◦ That means everyone in here
has their own gravitational
field!
◦ Larger objects have stronger
gravity
 Humans=barely measureable
gravitational pull

On Earth, gravity causes all
objects to fall at 9.8m/sec (32
feet/sec)
◦ All objects fall at the same rate,
no matter how much mass they
have
 Any difference in falling speed is
because of air resistance

We can use gravity to figure out
the mass of a planet
◦ We look at the size of the orbit of its
moons, and the speed the moons are
moving around the planet
◦ Next, we can figure out how strong
the gravitational pull is between the
moon and the planet
 Heavier planets=faster moons
 If a planet doesn’t have a moon, we
can watch how it reacts when the
orbit gets near to other planets