Newton’s Law of Universal Gravitation 5-5 Quick notes

Newton’s Law of Universal Gravitation
Quick notes
Reading Questions
1. Why was Newton’s Theory of gravity hard to accept at the time (why did
people have difficulty with the idea that a force keeps the moon tied to the
2. What is the centripetal acceleration of the moon?
3. The acceleration of the moon toward the Earth is about _______________as great
as the acceleration of objects at the Earth’s surface
(.00272m/s2/9.8m/s2g=1/3600g) .
4. The moon is ________ times further from the Earth’s surface than objects on
the Earth’s surface.
5. ______________2 = 3600! So FG is inversely proportional to the square of the
distance an object is from earth! Written:
6. In other words the farther an object is from the earth the _________the force of
gravity by ___________________.
7. The force of gravity is ____________________ __________________________ to an object’s
mass. This comes from Newton’s ______________law. ( equal and
8. The magnitude of gravity is proportional to _______________ _____________ masses.
9. So the equation for the force of gravity between two object’s is :
10. This leads to the law of universal gravitation which states:
11. Called the inverse square law it is written:
12. What is the value of the constant G?
13. Who first calculated the value of G?
14. Look at Example 5-9. Can you attract another person gravitationally? Look
at the solution and describe it below:
15. Look at Example 5-10 and notice the easier way to calculate this problem.
Explain how you could use this to calculate that Force of gravity on the
Do problems 28 , 31 and 40 below: