1. March 1 & 4 Homework Due Read & Study 12.1-12.4; do #1-7 p. 180 **Grade will be worth 5 points; ½ point per question and 1.5 points given to a randomly selected problem the teacher will grade on CORRECTNESS** Tonight’s HW Read & Study 12.4-12.6; do #8-13 p. 180 **Grade will be worth 5 points; ½ point per question and 2 points given to a randomly selected problem the teacher will grade on CORRECTNESS** Do Now - Last chance to claim your poster / fix it if it fell down? Any left by next Wednesday will be thrown away! - Take a clicker In your notes, please write Q&A: Action: Earth pulls moon. What is the reaction? What is stronger – action, reaction, or same? What Law defends your answer?

2. Action: Earth pulls moon. - What is the reaction? - What is stronger – action, reaction, or same? - What Law defends your answer?

3. Action: Earth pulls moon. What is stronger – action, reaction, or same? 1.Action(Earth pulls moon) 2.Reaction (moon pulls Earth) 3.Same!

4. What law defends your answer? 1.1 st Law 2.2 nd Law 3.3 rd Law

5. Google… PHET Gravity and orbits Click the first link Run the simulation and complete the Lab Activity Sheet. – This is due in 30 MINUTES for a grade – you will (10 points based on completion) – Then, we will have a graded, individual, 30 point POST LAB to assess this lab activity.

6. #1 –Why did Newton think there must be a force acting on the moon? 1.It moved in a straight line, not a circle 2.It moved in a circle, not a straight line 3.I had no clue how to answer this question

7. #2 What did Newton conclude about the force that pulls apples to the ground and the force that holds the moon orbit? 1.They were different forces 2.They were the same force 3.I had no clue how to answer this question

8. #3 If the moon falls, why doesn’t it get closer to Earth? 1.It has a large tangential speed, so it falls around Earth and not into it 2.It has a small tangential speed, so it falls around Earth and not into it 3.I had no clue how to answer this question

9. #4 What is meant by tangential speed? – Popcorn…

10. #5 How did Newton check his hypothesis that there is an attractive force between Earth and moon? – Popcorn…

11. #6 What is required before a hypothesis can become a theory? – Popcorn…

12. #6 What is required before a hypothesis can become a theory? – Popcorn…

13. #7 Since there is gravity between the planets and the sun, why don’t the planets crash into the sun? 1.They have small tangential speeds, so they fall around sun and not into it 2.They have large tangential speeds, so they fall around sun and not into it 3.I had no clue how to answer this question

14. Choose the picture you think shows the gravity forces on the Earth and the Sun. A. B. C. D. E.

15. How would these gravity forces change if the Sun got more massive? A.Increase B.Decrease C.Stay the same

16. How would these gravity forces change if the Earth was much closer to the Sun? A.Increase B.Decrease C.Stay the same

17. How would these gravity forces change if the Earth got much less massive? A.Increase B.Decrease C.Stay the same

18. How would these gravity forces change if the Earth and Sun were moved farther apart? A.Increase B.Decrease C.Stay the same

19. Choose the picture of how the Earth would move if you “turned off” the gravity forces. A. B. C. D. E.

20. Changes to make to your post lab: Make sure #2 and 4 say massive Change the answer choices in #11 to “enjoyable” rather than “useful” When you are done… Place in in box upside down; RETURN CLICKER IN ORDER; silently BEGIN your HW