1. The attractive force between two
objects is known as:
2. __________ is the resistance of an
object to a change in motion.
Lesson Essential Question:
How do gravity and inertia determine the
orbits of solar bodies?
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Go over Bellringer
Pass back graded papers
Define and act out force
Read and discuss the two factors that work
together to keep the Earth and Moon in orbit with
one another.
• Complete the Gravity and Inertia graphic
organizer
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Force
A push or a pull exerted on an
object.
Gravity
The attractive force between two
objects.
Bill Nye Gravity YouTube
What is Gravity
Bill Nye Gravity Rap
Law of Universal Gravitation
The scientific law that states that every
object in the universe attracts every
other object.
Gravity
The strength of the force of gravity between two
objects depends on two factors: the masses of
the objects and the distance between them.
Mass – the amount of
matter in an object
(doesn't change
depending on
location)
Weight – the force of
gravity on an object
(can change
depending on
location)
Gravity
The strength of the force of gravity between two
objects depends on two factors: the masses of
the objects and the distance between them.
Gravity Versus Distance
As a rocket leaves a
planet’s surface, the
force of gravity
between the rocket
and the planet
changes. Use the
graph to answer the
following questions.
Question:
What two variables are
being graphed? In what
units is each variable
measured?
Answer:
Force of gravity on
the rocket in millions
of newtons and
distance from the
planet’s center in
planetary radii
Question:
What is the force of
gravity on the
rocket at the
planet’s surface?
Answer:
Four million
newtons
Question:
What is the force of
gravity on the rocket
at a distance of two
units (twice the
planet’s radius from
its center)?
Answer:
One million newtons
Inertia
The resistance of an object to a
change in motion.
Newton’s First Law of Motion
An object at rest will stay at rest and an
object in motion will stay in motion
with a constant speed and direction
unless acted on by force
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Gravity and Inertia
Newton concluded that two factors –
GRAVITY and INTRTIA – combine to keep
the moon in orbit around Earth.
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Gravity & Inertia Video
Friday, March 18, 2016
Quiz Monday on
Earth’s Movement.
Study guide in
Ebackpack.
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1. Cards will be distributed to individuals
or pairs. One student will read their
card, staring with the prompt “Who
has….” The student who has the
matching vocabulary word will stand up
and respond “I have…Who has…”