Transcript This Gravity Review PowerPoint Video

Gravity
Reassessment Review Instructions
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Click “Slideshow” then “From Beginning”
Read each slide carefully.
After reading takes notes from every page.
Organize your notes with subtitles.
Memorize your notes.
Isaac Newton
• Sir Isaac Newton was one of the
greatest scientists and
mathematicians that ever lived.
• Isaac Newton was the first person
to hypothesize that the force that
pulls an apple to the ground also
pulls the moon toward Earth,
keeping it in orbit.
Forces
• A force is a push or a pull.
• Force gives an object the energy to move,
stop moving, or change direction.
• When you write with a pen you exert a
force. When you peddle your bike, blow
your nose, turn on a faucet, chew your gum,
or swimming in a pool, you are exerting
forces on other objects.
• We would never be able to move without
exerting forces on things.
Force
• A force can be balanced which means objects
motion will NOT change. When all forces on the
object are combined the net force is 0N.
• An unbalanced force gives an object the energy to
move, stop moving, or change direction. When all
forces on this objects are combined the net force
will NOT equal 0N.
Force of Gravity
• Newton was the first person to seriously
study gravity
• Gravity is a force that attracts all objects
toward each other.
• The force of gravity is measured in units
called Newtons (N).
• Click Here to watch Gravity BrainPop
(u.n. – harpool, p.w. - longhorns)
Gravity Measures Weight (not mass)
• Mass- is the amount of matter in an
object and does not change on other
planets.
• Weight- is the force of gravity on an
object and can change on different
planets due to their different
gravitational pulls.
• The greater the mass the greater
the force (weight)
• Weightlessness – free from the
effects of gravity
Watch This
Gravity
• The strength of gravity between two
objects depends on two factors:
• 1. masses of the objects (If mass
increases, force also increases)
• 2. distance between the objects (If
distance increases, force decreases)
Gravity
Gravity Summary
 Gravity is the force that attracts all objects
towards each other due to their masses.
The greater the mass of an object, the greater
the gravitational force.
(the more mass it has the harder it pulls; less mass will pull less)
The greater the distance, the less the force
(the closer it is the harder it pulls; the farther apart the weaker the pull)