## Sunday, June 27, 2010

### Apologia Physical Science, Module 11, The Forces in Creation - Part 1

• Create an account and make your own flashcards at Quizlet.com!

• Centripetal Force - Animations and some good information!
• Definition of Centripetal Force - "A center-seeking net force that is required in order to keep moving objects in a circular path.  If the requirement is not met, then objects move into larger curved paths, or go off on a tangent as they follow Newton's First Law."  (inertia)
"Centrifugal" Force: The False Force - Another excellent animation that clearly shows what is happening, and more information.
• Definition of Centrifugal Force - "A non existent force which is actually the absence of centripetal force."
Find these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)

(1) p. 261, The Four Fundamental Forces of Creation

0:00 - 1:54 from this video

(2) p. 262-265, The Gravitational Force

Gravity
"Rate of acceleration of a falling object is roughly 10m/sec²."
We learned that it is 9.8m/sec², but remember, this video says "roughly."

(3) p.  265b-269, Force and Circular Motion

Centripetal Force, Steve Spangler
Cool and fun!  4 glasses on a tray, spinning around!!!

Centripetal Force
Very similar to the experiment we do in Apologia

(4) p. 269b-273, The Gravitational Force at Work in Our Solar System

► Neat visual of the distances between planets.  Sizes are not to scale.

The Relative Size of the Planets and the Sun

Orbits of the planets and comets.
You can see that Mercury revolves faster around the sun.
Look on p. 271 for the approximate time for each planet.

Meteorite Crash in Canada Filmed by Police Cam,
Nov. 2008

(5) p. 274-276, Comets

A Comet's Nucleus, and how the Comet's Tail reacts when orbiting the sun

Planets and the Kuiper Belt

(6) p. 277-281, What Causes the Gravitational Force?

Albert Einstein's General Theory of Relativity
I don't understand this one at all, but it is a theory, (as is the theory of gravity). =)

Excellent graphics.

Graviton Theory

(7) p. 281c-284, A Brief History of Our View of the Solar System

Ptolemaic vs. Copernican Theories
Ptolemy's theory (geocentric - earth is in the center) for the first half of the video,
then Copernicus' theory (heliocentric - sun is in the center).

100 Greatest Discoveries - Astronomy
This is the first 23 minutes of the video to go along with Debbie's Video Viewing Guide.
You can watch the entire video here.

1. I stumbled across your blog while looking for clarification of how to do experiment 11.1. What a fantastic resource you have made. Thank you very much!

2. Thank you. =)
So glad it can be of help to you.

If you're talking about centripetal force (I used 1st Edition - not sure what Exp. 11.1, 2nd Ed. would be), we had a hard time keeping count while swinging, so we had one kid to count his own swings, and the other would keep time.
Here is the post at Sahm-I-Am that may help a little. Or not! =D
http://martysahm.blogspot.com/2010/07/physical-science-module-11-forces-in.html

3. This was very helpful. THANK YOU SOOOO MUCH!!

1. You're welcome! =)

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