Download Gravity: The Invisible Force (Planetary Unit)

Gravity: The Invisible
Force
Science
Ms. Twardowski
CMS – 8 Tan
What do YOU know about gravity?
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With your partner, make a list of everything you
know about gravity. There are no right or
wrong answers.
Use these words to help you make your list:
weight,the Moon, mass, distance, outer
space,etc.
You have five (5) minutes!...GO!
Yes or No?
(red/green card)

The Moon affects the
ocean’s tides.
Guess what?!!!
Don’t copy this…
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Right now you are being pulled downward by
the Earth’s gravity; it’s the force that you
commonly call ‘your weight’.
BUT…you are also being pulled on by Mar’s
gravity, Pluto’s gravity, and by the gravity of
many other planets and stars outside of our
solar system.
The Fantastic Four!!!
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There are four fundamental forces in our
universe:
Strong, Weak, Electromagnetic, AND…
Copy this!!! Gravity: an attractive (pulling)
force between objects. That means, ALL
objects in the universe! These objects can have
a force on one another without even touching!
How does mass affect gravity?
Does this question seem familiar? Hint: it’s on the
whiteboard!

Copy this!! The
amount of force
between objects
depends on its mass.
If the mass increases,
so does the force of
gravity.
Wait! How did that get in here?!
Ms. T. – 9th
grade
basketball
(1984)
How does distance affect gravity?
How about this question? Hint: EQ.

Copy this!! If the
distance between two
objects increases, the
force of gravity will
decrease; BUT the
force of gravity
NEVER goes to zero!
Our Solar System

The Sun and the planets have a gravitational pull on each other,
BUT since the Sun is SOOO much more massive than any
planet, its gravity dominates the solar system and that’s why
planets orbit the Sun.
The Earth and Moon
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The Earth’s gravity is
responsible for keeping
our Moon in orbit
around our planet.
The Moon’s gravitational
pull on the Earth affects
our ocean’s tides.
Yes or No?
(red/green card)

The planets of our Solar System revolve around
the Sun because the Sun is so massive (more
gravity).
Yes or No?
(red/green card)

The two main things that affect gravity are mass
and weight.
Which statement is true?...
Red = #1
Green = #2
1.
2.
The Sun has more of an affect on the Earth
because it is so big.
The Moon has more of an affect on the Earth
because it is so much closer to us than the Sun.