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Gravity. What makes the world go ‘round…. Review: Newton’s 3 rd Law. Properties of Gravity. Every object with mass has gravity… = gravity. Properties of Gravity. The larger an object is, the more gravity it has…. Bigger Gravity =. Properties of Gravity.
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Gravity What makes the world go ‘round…
Properties of Gravity • Every object with mass has gravity… = gravity
Properties of Gravity • The larger an object is, the more gravity it has…. Bigger Gravity =
Properties of Gravity • As objects get farther away, the force of gravity gets weaker… Gravity ,
Newton’s Law of Gravitation • Newton discovered how mass, distance and gravity were all related…
Newton’s Law of Gravitation • Newton’s Law States the FORCE of gravity is:
Fg Fg is the force of gravity pulling any two objects toward each other from any distance.
Newton’s Law of Gravitation G (gravitational constant) = m1 & m2 = mass of any two objects d = distance between the two objects.
Examples • Take a look at the first example on your notes sheet…
Another Look at Newton’s Law • Newton’s Law of Gravitation is an inverse square law… • Inverse Square Law: As d increases, Fg gets exponentially smaller. The variable in the denominator is squared.
What an inverse square looks like • Making a graph of Fg vs. Distance would look like this: Fg Distance
Back to the classwork… • From the classworksheet, divide the distance of #1 by the distance of #2. Ratio of distances: = ? • What do you notice?
Back to the classwork… • Divide the answer for Fg you got for #1 by the answer you got for #2. Ratio of gravitational force: = ? • What do you notice?
Using this relationship… • With an inverse square law, you can solve some problems using this chart, once you know Fg at one place…
What it looks like • You find Fg from some starting point using Newton’s Law… d Fg=1000N
What it looks like • When you double the distance (x2), the force gets divided by 22, or 4.… d d Fg=1000N/4=250N
What it looks like • When you triple the distance (x3), the force gets divided by 32, or 9.… And so on and so on…. d d d Fg=1000N/9=111N
Finishing Up… • Complete #3 and #4 on your classwork sheet.