Download Ch. 11.2 - BAschools.org

Chapter 11-2
Gravity
Law of Universal Gravity
 All
objects in the universe
attract each other
through gravitation forcedependant on mass and
distance
 Gravity 2
Gravity
 Attractive
force between
two objects
 Universal gravitation
equation
F=G(m1m2)
d2
Gravity Clip
Gravity continued
 All
matter is affected by
gravity
–Larger the mass the more
the gravity
–The closer the objects the
more gravity
 Earth-
Very large-strong
gravity. The moon is
close enough to still be
affected by its gravity but
not as strongly as
humans.
Gravity con’t
 Acceleration
due to
gravity is a constant
number – 9.8 m/s2
 We will ignore air
resistance so gravity is
the same for all
Free fall and weight
 Free
fall – to fall with only the
force of gravity acting upon
the object being pulled toward
the center of the earth
 Remember
a bowling ball
has more inertia than a
softball so if we figure in
air resistance it would
affect the lighter softball
slowing it down at the
same speed as BB
Weightlessness
 Apparent
weightlessness
–When all objects are freefalling
together toward the earth at the
same rate
–Example astronaut and shuttle
Weight
-
Amount of gravitational
pull on an object.
Dependant on the mass
of the object
 W= mass x gravity (9.8)
Weight
The SI unit for weight is
also Newton because the
formula is mass times
acceleration of gravity.
Terminal Velocity
 Final
velocity that a falling
object reaches because air
resistance and gravitational
pull equal each other
 Skydiver-200m/hr
parachute 120m/hr
 Space Jump Clip
Projectile motion
 Has
2 components
–1)Horizontal motion- motion
of an object that is in the
direction and velocity it was
thrown
Projectile motion
 2)Vertical
Motionmotion which increases
due to gravity pulling
the object toward the
earth