2. Unit 11 The Law of Universal Gravitation

3. Background info required Before you learn about Universal Gravitation.. You need to know where it resides within the governing forces for our world. Also…. You should be able to tell me the unit of measurement for Force. It is a ______________? We also say that Weight is a ___________?

4. FYI The next slide is not on your notes, you will need to write this info on your notes – either in the side margin or on your own paper.

5. There are 4 discrete FORCES that govern the interactions of matter. They are listed below in order of - STRONGEST to WEAKEST. 1.Strong Nuclear Force – responsible for keeping quarks together inside protons and neutrons 2.Electromagnetism – range is infinite, has + & - charges that can combine or cancel each other out. 3.Weak Nuclear Force – responsible for radioactive decay 4. Gravity- range of gravity is unlimited & exist bet. 2 masses & the dist. bet. them.

6. Gravitation is Universal Gravity arises from the warping of space and time. Gravity is a way masses communicate with each other.

7. Tangential Velocity Refresher What is it ? And What does it look like?

8. Hopefully, you were thinking…. It is  Linear And it looks like  A straight line coming off a point on the circle.

9. Space -Time Warp Tangential velocity of the Earth allows it to fall around the sun rather than falling directly into the sun and crashing into it.

10. The Law of Univ. Gravitation states.. Every particle attracts every other particle with a force that is proportional to the mass of the particles and inversely proportional to the square of the distance between them.

11. There is a constant that is used in this formula ( G ) The Universal Constant of Gravitation Which is: G = 6.67 x 10 -11 N * m 2 / kg 2 It is also written with F g and F grav w/ the G written in a different location.

12. When solving, it looks like…. Force = (universal constant of gravitation) ( mass 1) Mass 2) (distance) 2 The unit for Force is Newtons.

13. The proportionalities expressed by Newton's universal law of gravitation can also be represented graphically. Go to: http://www.physicsclassroom.com/Class/circles/u6l3c.cfm http://www.physicsclassroom.com/Class/circles/u6l3c.cfm And discuss proportionality info

14. Problem Solving Go to pg. 97 in the Problem Solving Exercises Physics Workbook. Read pg. 97. Then, review example 1, 2, and 3. Next, complete Practice Exercises 1, 3, & 5 on pg. 98 – 100.

15. Check your work!! The answers to # 1, 3, and 5 can be found on pg. 249. You must have work shown for your answers to receive credit for this activity.