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.

March 1 & 4Homework 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 clickerIn 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?

Action: Earth pulls moon. - What is the reaction?

- What is stronger – action, reaction, or same?

- What Law defends your answer?

Action: Earth pulls moon.

What is stronger – action, reaction, or same?

1 2 3

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1. Action(Earth pulls moon)

2. Reaction (moon pulls Earth)

3. Same!

What law defends your answer?

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1. 1st Law2. 2nd Law3. 3rd Law

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.

#1 –Why did Newton think there must be a force acting on the moon?

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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

#2 What did Newton conclude about the force that pulls apples to the ground and the force that holds the moon orbit?

1 2 3

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1. They were different forces

2. They were the same force

3. I had no clue how to answer this question

#3 If the moon falls, why doesn’t it get closer to Earth?

1 2 3

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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

#4

• What is meant by tangential speed?– Popcorn…

#5

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

#6

• What is required before a hypothesis can become a theory?– Popcorn…

#6

• What is required before a hypothesis can become a theory?– Popcorn…

#7 Since there is gravity between the planets and the sun, why don’t the planets crash into the sun?

1 2 3

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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

Choose the picture you think shows the gravity forces on the Earth and the Sun.

A. B. C. D. E.

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A. B. C. D. E.

How would these gravity forces change if the Sun got more

massive?

A. B. C.

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A. Increase

B. Decrease

C. Stay the same

How would these gravity forces change if the Earth was much

closer to the Sun?

A. B. C.

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A. Increase

B. Decrease

C. Stay the same

How would these gravity forces change if the Earth got much less

massive?

A. B. C.

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A. Increase

B. Decrease

C. Stay the same

How would these gravity forces change if the Earth and Sun were

moved farther apart?

A. B. C.

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A. Increase

B. Decrease

C. Stay the same

Choose the picture of how the Earth would move if you “turned

off” the gravity forces.

A. B. C. D. E.

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A. B. C. D. E.

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