to the image on the next slide.
was a “founding father” of physics.
As the story goes, Newton, a young scientist, was staying isolated in the country to avoid being exposed to the plague of 1665.
He was relaxing under a tree in an apple orchard enjoying the fresh country air
when he saw a ripe apple fall off a branch
on to the ground.
the mysterious FORCE that holds
the Moon in orbit around the Earth.
With this in mind, Newton wondered
if the FORCE that holds the Moon
in orbit is the same FORCE that makes the apple fall to the ground?
Newton’s pondering of this
question eventually led to his answer:
the greater the FORCE of ATTRACTION.
It exerts a large FORCE of ATTRACTION
This pull of the Earth on all objects with a mass is called gravity!
The pull of gravity is why we do not float away.
you are measuring the pull of the Earth's gravity on YOU!
the pull of the Earth's gravity
on you in POUNDS.
the same on the Moon,
as you do on the Earth
than on Earth.
The Earth is bigger and
more massive than the Moon.
You weigh about SIX times more
on Earth than on the Moon!
you weigh the most
object in the solar system
your weight on Earth x mass-of-the-planet
divided by the planet's radius2
the rocks fly off the Moon and hit the Earth?
The distance between two objects
affects the PULL of Gravity.
The greater the distance between
two objects, the less the PULL of Gravity.
The distance between the Earth and Moon
is very large. The Moon rocks are just
too far away to be pulled down to Earth!
get bigger, as you increase
the mass of one of the balls?
2. Does the smaller ball feel
a greater force of gravitational attraction than the larger ball?
3. As the distance between balls decreases, how does the force of gravitational attraction change?
the red button.
above each ball changes.
the greater the attraction between them.
2. NO, the force of attraction between balls
is equal. It's proportional to m1 X m2.
3. Increases: the closer the balls are together,
the greater the force of gravity.
which will hit the ground first, the duck or the book
in the air
at exactly the
at exactly the same time!
from the same height.
from the same height.
What happens and WHY
many people believed that
the larger object would land first.
Galileo insisted on TESTing IT!
That is exactly what you just did.
Galileo is said to have dropped his
test objects from the Tower of Pisa.
an object's center of gravity.
the clown in your kit.
from the tip of your finger?
on your finger!
Try the tip of your nose!
You have changed the clown’s CENTER of gravity.
on each hand
of the clown.
Balancing on the Tip of a Pencil Trick.
on the tip of a pencil
by lowering its
center of gravity
with two forks.
based on the CENTER of GRAVITY.
of a paper truck, you will need:
to the coin.
to the paper clip.
to poke a hole near
a corner of the truck.
Hang the truck
from the paper clip.
Let the weighted
string come to rest.
where the string
makes a line.
corner on the truck.
Repeat step 5.
to draw the line
made by the string.
to mark the second line.
you may not have found the exact center.
Move the tack until you pinpoint the true center of gravity.
to be concentrated. If supported at this point,
the body remains balanced.
the truck should balance.
two lines cross is the
CENTER of GRAVITY!
the Center of Gravity
tends to WHAT
between objects affect
objects affect the force
of gravitational attraction
two masses, the greater the force.