Download Notes 3-2 Gravity Objective: Describe projectile motion and circular

Notes 3-2 Gravity
Objective: Describe projectile motion and circular motion.
CLE 3202.3.2 Investigate and apply Newton’s three laws of motion.
Objective: Explain the difference between gravity, mass and weight, and calculate weight
of an object.
CLE 3202.4.1 Explore the difference between mass and weight.
CLE 3202.4.2 Relate gravitational force to mass.
A.
________________________ is one of the four basic forces that also include the
electromagnetic force, the strong nuclear force, and the weak nuclear force.
B.
Law of gravitation states that any _________________________________________
exert an attractive_____________________ on each other.
Gravitational force depends on two factors:
1. _____________________________________– the more mass the stronger the pull.
2. ____________________________between the objects - ______________________
____________________________________________________________________
C.
_____________________ is an attractive _______________________ between any
_______________________ that depends on the ___________________of the objects
and the _________________________ between them.
D.
No matter how far apart two objects are, the gravitational force between them
_______________________completely ________________________________.
E.
Because the gravitational force between two objects never disappears, gravity is called a
long- range force that gives the universe its structure.
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F.
Isaac Newton formulated the law of universal gravitation, which he published in 1687.
Due to _______________________, all objects fall with the same acceleration regardless
of mass. All objects near the surface of the earth ____________________________ due
to the force of gravity.
Force of Gravity
f =
m =
a =
G.
Weight and Mass
1. Weight and mass are ____________________________________ but are related.
2. ______________________________________________________ exerted on an object.
3. The __________________________is measured in ______________________________
4. __________________ a measure of how much __________________ an object contains.
5. The weight of an object can change, depending on the gravitational force on the object.
6. Weight _____________________________as an object moves away from Earth.
7. The more ___________________________(matter) an object has, the more it weighs –
the __________________________________the gravitational force is.
8. Weight _________________________________________________________________.
Earth’s Gravitational Acceleration
H.
1. When all forces except gravity acting on a falling object can be ignored, the object is said
to be in ________________________________.
2. Close to Earth’s surface, the acceleration of a falling object in free fall is about _______.
I.
Free-fall
Objects in the space shuttle float because they have no force supporting them.
J.
_________________________when an object is influenced only by the force of gravity.
K.
__________________________-sensation produced when an object and its surroundings
are in __________________________-object is ___________________weightless!
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L.
__________________________________ its surroundings are falling at the same rate so
they don’t exert a force on the object.
Weightlessness
– surroundings are falling at the same rate so they don’t exert a force on the object
_______________________– anything _________________or shot through the air.
1. Projectiles have horizontal and vertical velocities due to ___________________
and ___________________ and follow a curved path (parabolic path).
2. Gravity pulls the object toward the earth. Inertia resists the pull of gravity. This
causes a curved path. (parabola)
Draw and label the picture!
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If you were to throw a ball as hard as you could from shoulder height in a perfectly
horizontal direction, would it take longer to reach the ground than if you dropped a ball
from the same height?
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Surprisingly, it ____________________________ Both balls travel the
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___________________ vertical distance in the same amount of time.
Circular Motion
1. Acceleration toward the center of a curved path is called _____________________________.
It is caused by centripetal force, an unbalanced force.
2. __________________________________= directs an object moving in a circular pattern
toward the ________________________ of the circle.
3. Centrifugal Force = pulls the object away from the circular path.
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When a car rounds a curve on a highway, a centripetal force must be acting on the
car to keep it moving in a curved path.
This centripetal force is the frictional force, or the traction, between the tires and
the road surface.
Anything that moves in a circle is doing so because a centripetal force is
accelerating it toward the center.
Imagine whirling an object tied to a string above your head.
The string exerts a centripetal force on the object that keeps it moving in a
circular path.
In the same way, Earth’s gravity exerts a centripetal force on the Moon that keeps
it moving in a nearly circular orbit.
Review Questions:
How do weight and mass differ?
TRUE or FALSE:
An astronaut on the Space Shuttle feels weightless because there is no gravity in space.
Why?
Describe the path of a marble as it leaves the spiral tube shown below.
Gravity is an attractive force between any two objects and depends on :