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Announcements 10/03/11

Check course calendar– Find link to lesson(s) for the week– Check out assignments

Course Pack should be available before Thursday at UBS.– Spectral analysis (preparatory work + exercise)– Print your own copies for color

Will get “real” star finder on Tuesday (please return card-stock ones to TA)

Open House Jacobsen Observatory - Weds. 9 pm (7 pm is full) - if clear!

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Loose ends - Sky View Cafe

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Loose Ends - Quarks

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Distinguish among the following kinds of energy

kinetic

thermal

gravitational potential

electric potential

radiative

mass energy

Give examples of how energy is conserved.

Learning goalsLearning goals

MATTER AND ENERGYMATTER AND ENERGY

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The Atom + isotopes & ions

An atom that has lost 1 or more electrons

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Nomenclature you need to know

Astronomers note how many electrons the atom has lost through Roman numerals.

H I = neutral hydrogenHe II = singly ionized heliumCa II = singly ionized calcium

Fe IV = iron atom has lost 3 electronsFe XII = iron atom has lost ___?___ electrons

___?___ = oxygen atom missing 2 electrons

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States of matter

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Video taken by satellite STEREO

PLASMA

http://en.wikipedia.org/wiki/File:Encke_tail_rip_off.ogg

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Kinetic vs Gravitational Potential

KE = ½ mv2

GPE = mgh

Energy

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Thermal

Energy

Thermal energy is a measure of the average kinetic energy of a system of particles.

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Radiative

Electric Potential

Energy

+ -

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Gravitational Potential

vs

Electric Potential

Energy

13E = mc2

Mass EnergyMass Energy

Sun’s CoreSun’s Core

FusionFusion

Fission

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Learning Goals

Relate each of Newton’s laws of motion to terrestrial and celestial events

Demonstrate knowledge of how the force of gravity depends on the masses of the objects and the distance between them through mathematical analysis.

Explain what we mean by conservation of angular momentum

Newton’s Laws of motion + GravityNewton’s Laws of motion + Gravity

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Newton’s 1st Law of Motion

An object resists its change in state: an object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force.

Relate each of Newton’s laws of motion to terrestrial and celestial events

Terrestrial example

Celestial example

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Newton’s 2nd Law: a = F/m

Terrestrial example

Relate each of Newton’s laws of motion to terrestrial and celestial events

Celestial example

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Newton’s 3rd law

For every action there is an equal and opposite reaction.

Terrestrial exampleRelate each of Newton’s laws of motion to terrestrial and celestial events

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How gravitygravity “works”

€

Fgravity =Gm1m2

d2

2R

MmGFg =

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Inertia as experienced by a sperm whale and a bowl of petunias

€

F ∝Mm

R2

a =F

m∝Mm

R2

1

m∝M

R2

g =GM

R2

weight = mg

Whale weighs a lot more!Experiences a much greater force of gravity. Why, then, would the whale and bowl of petunias fall at same acceleration? (They also have same velocity when they hit, but NOT the same kinetic energy.)

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Conservation of ANGULAR momentum

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Explanation: