Newton & Gravity

Newton had to apply ____________ to ___________ forces and show the equation still worked. His biggest task was _______________. This work resulted in an ___________ for the amount of ____________ ______________between any ___________ objects.

But Newton had to make 3 _____________:

• (1) Gravity pulls ONLY toward the _______________ of an object.
• (2) You HAVE to have ____________ objects. (This implies that a ________ object has no gravitational attraction- something ____________ proved wrong.)
• (3) _________ particle in the __________ pulls on ____________ other particle. (i.e. Nothing is immune to gravity. Not even "nothing" (_______) as ___________ proved.

  The first force (of the 4 known) to be written as an ______________ was gravity!

  And the equation is: F = Gm₁m₂ where "m₁" is the ______ in ____ of the 1^st object

  r² (like a star, planet, etc.) and m₂ is the ______ in ____ of the 2^nd object "r" is the distance from one object to the other Planet

  in ___________

  (r= __________)

  r

  "F" is the __________ in ____

  and G = 6.67*10^-11 _____________ called the

  "____________________________________"

  because it's the same anywhere in the universe and does not change. (All the _________ have a constant. _____________ constant is the smallest and that makes it the __________ force. The number is so small, Newton __________ never being able to _____________ it. It would be more than a ____ years (____) before a brilliant experimenter, Henry ______ performed an experiment so ________ and clever to measure the number. Side note: U.S. Naval Observatory has noticed ___________ in ____. In fact, it can be argued that we have know way of knowing if any Universal Constant is really _______________.

• The ________ you are to the _______ of an object the greater the ___________ force.
• The ________ around the object is called a ______________ ___________.

  You can get an equation to find the ____________ acceleration, "__", for a planet using this ___________ with ___________:

  Just set F=mg equal to F = Gm₁m₂ and one of the "m"s cancels out (remember

  r² __________ said that the _________ of an object did not affect how __________ it fell! Here's the mathematical proof!)

  mg = Gm₁m₂ and you get "g = _________"

  r²

  Facts on Gravity:

  Weakest force

  The __________ the mass, the _________ the gravity.

  The _________ ______ objects are, the ___________ the gravity.

  If it has ________, it has gravity, no matter _____ _________.

  Gravity only ever _____________. All the other forces ________ AND ________. (Why!?)

  _________ and _______ ARE NOT THE SAME THING! ___________ is when gravity pulls an object downward like an ____________ sitting on your chest. In deep space, where there is ______ ___________ the __________ sitting on your chest would exert ____ ___________ because there is no __________ pulling it down onto your chest! But it still has __________, 'cause the __________ is still there.

  __________ is just a count of how many _________ there are in an ___________.