Chapter 4 Gravitation and the Waltz of the Planets

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Physics of Astronomyweek 4, winter
2004 Celestial Mechanics

• Star Date
• Review motion of Moon and Mars
• Starry Night animations
• Jupiters size and distance workshops
• Gravity review Physics Ch.3-6
• Figures for Astrophysics Ch.2
• Learning plan

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Use Keplers 3d law to weigh Jupiter
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Gravity review Physics Ch.3-6

• Ch.3 Kinematics in 2D Vectors
• Review vectors.
• Add component by component.
• Forces in the y direction do not affect motion
  in the x direction
• Uniform circular motion
• Galilean relativity Motion of an object
  depends on the motion of its reference frame

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Physics Ch.4 Newtons Laws

• SForce mass acceleration, where a dv/dt
• N1 Law of Inertia Every body continues in
  its state of rest or of uniform speed in a
  straight line as long as no net force acts on it.
• N2 SFma The acceleration of an object is
  directly proportional to the net force acting on
  it and is inversely proportional to its mass.
  Acceleration is in the same direction as the net
  force.
• N3 Action Reaction Forces are
  INTERACTIONS Whenever one object exerts a force
  on a second object, the second exerts an equal
  and opposite force on the first.

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Physics Ch.6 Gravitation Newtons Synthesis
We derived Keplers 3d law (phenomenological)
from Newtons 2d (theory) Near the surface of
the Earth, Fmg. Derive g from the mass M and
size R of Earth g is approximately constant
close to the surface of the Earth, but weakens
with altitude. Newtons law is
indistinguishable, in most cases, from
Einsteins insight that gravity is due to the
curvature of space near massive objects.
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Astrophysics Ch.2
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Learning Plan for weeks 3-4
Mon.26.Jan Workshop on Jupiters moons Dark
matter Tues.27.Jan HW due on Universe 34
Quiz Review Physics Ch.34 ML Physics
Ch.6 Thus. 28.Jan Lecture and ML on Astrophysics
Ch.2 Tues.3.Feb HW due on Physics Ch.6 CO
Ch.2 Quiz
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Assignments for week 4
Tues.27.Jan HW due Physics Ch.6
54 Universe Ch.3 23, 24, 33, 30, 43, start
45 Ch.4 36, 48, 52 (50), 35, 39, 44 Review
Physics Ch.34 ML Physics Ch.6,
Gravitation Team 1 Ch.6.1-3, 13, 14 Brian
Mary Team 2 Ch.6.4-5, 28 Erin Jenni Team
3 Ch.6.6-8, 47 Annie Tristen Thus. 28.Jan
Lecture on Astrophysics Ch.2 Team 4
Ch.2.12.2, 2.1 2.2 Matt Zita Team 5
Ch.2.3, 2.7 Joey Jared Tues.3.Feb HW due
Physics Ch.6 13, 14, 28, 47, 57, 60 CO
(Astrophysics) Ch.2 1, 2, 7, 8, 11