►This site was originally created for my kids and their cousins, because we did science together. We eventually added more friends and I ended up having science classes for five years. I am no longer adding to the site (since 2014), but will leave it up for others' use. I do post to facebook occasionally if I come across something to share. =)

►Please accept my apology for any broken links or videos that do not work. I am always disappointed when people take down their videos from YouTube. It makes it hard to find just the right replacement. And because the videos were posted years ago, I usually have no recollection of what the video was about.
I kept thinking I would have time after my kids graduated, but life has filled up my free time with new responsibilities. =)

►Please do not email, asking me to post your website link, or to review something to put on my site. Any resources posted on this site are things I had found on my own during my regular searching for material I needed at the time, and liked it well enough to post here. There have never been any affiliates on my site, and as it is no longer active, would not be worthwhile at this point. ;)
Thank you!

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

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

Other Study Links
• 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

"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.