Conceptual Physics

http://mrlafazia.com/PHYS111/lessons/201011Fall/PHYS111_21.ppt

THURSDAY November 4th, 2010LESSON GOALS:

• Continue our series of Lunar discussion questions as a class• Discuss the Big Bang Theory and its implications• Watch video segments on the Big Bang (Theory of, Evidence for, and Replication of)• Demonstrate Gravity Simulator program

• solar system & earth-moon system simulations• Share thoughts on gravity Discussion Prompt • Calculate Earth-Moon gravitational force magnitude

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Lunar Study Questions

We will now continue our look at some of the important questions regarding our nearest celestial neighbor—Luna.

Recall that these questions relate prior content and experiences to the Moon-Earth-Sun system.

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Lunar Study Questions 9-13

9) How does a partial or total eclipse of the Sun occur?10) How does a partial or total eclipse of the Moon

occur?11) When does a full moon occur?12) How does the Moon’s diameter compare to the

Earth’s?13) Why do the Sun and Moon appear to be

approximately the same size “in the sky” even though the Sun is able to encompass millions of Moons within itself?

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Lunar Study Questions 14-18

14) What might happen if the Earth did not rotate on its own axis as it revolves around the Sun?

15) Explain what happens with high and low tides.16) Considering the Sun’s effects (about 1/3,

gravitationally, as the Moon’s), when would you get the biggest difference between high and low tides?

17) Why is the Moon getting further and further away from the Earth (i.e., why is it “less tightly bound”)?

18) How is the Moon (theoretically) supposed to “meet its end” if given enough time…?

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Discussion: The Big Bang

• Discussion: “What is the Big Bang Theory and what does it propose”?– “How does this relate to the idea of Energy

Conservation”?– “Is there just one version of the Big Bang Theory”?

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Video Segments: The Big Bang

• Segment 1: Theory Behind the Big Bang (3 mins)• Segment 2: Evidence for the Big Bang (6 mins)• Segment 3: Replicating the Big Bang (3 mins)

– After each clip we may discuss what was presented.• Any questions which arose should be brought up during

that time.

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Gravity Simulator: Part 1

Our Solar System and the importance of gravitational stability…

“What happens when we delete a planet?!”

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Gravity Simulator: Part 2• Making our OWN Earth-Moon system

– Each group must research one aspect of the Moon…• Size (in kilometers) (meaning Diameter)• Mass (in kilograms)• Semi-Major Axis (in kilometers) (relates to distance from Earth)• Eccentricity (how “elliptical” its orbit is)• Inclination (where it is in relation to the Earth’s equator)

– “What effect does the Earth have on the Moon”?– “What effect does the Moon have on the Earth”?– “How long does it take the Moon to complete its orbit”?

• “Does this make sense”??– “What happens when we delete the Earth?!”

• MAKE PREDICTION and THEN test it.

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Discussion Prompt: gravity

“It is often a misconception that other planets do not exhibit gravity of their own. Think about space exploration. How would other planets NOT “having” gravity make space travel MORE DIFFICULT”?

Think about this individually (make some notes for your own reference) and then we will share our ideas and discuss.

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Calculation: Earth-Moon attraction

• Using Newton’s Law of Universal Gravitation, work out the gravitational force acting between the Earth and the Moon.– “Does it matter which object’s ‘Point of View’ you

consider”?• WHY or WHY NOT?

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Recommended Reading:

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• p. 105, Sections 6.1 – 6.5, 6.7 – 6.11

Note: The text does not offer much specific help on Earth and Space topics, so we will rely mostly on outside sources for our references for the majority of this unit.

Looking Ahead:

12/12

• Next class we will discuss Solar Evolution and get some more practice on the Law of Universal Gravitation.