Physical Science, Module 10, Newton's Laws, Part B

 --Videos we watched for Module 10.
--This is an excellent resource with interactive links:  Newton's Physics Notebook
--Find relevant links at Physics4Kids. Laws of Motion and Forces are good ones for this Module.
--Play  Quizlet.  Just scroll down and click on Physical, then scroll to find the Module you want.

Disclaimer:  In these pics, it seems as if only my daughter is doing something!  But in the videos, you can see they all take part.

Experiment 10.4, Newton's Third Law
The kids LOVED the experiment today!  Something exploding.  =D
Newton's third law says that for every action, there is an equal and opposite reaction.  When we mixed vinegar and baking soda in a bottle, then capped it with a cork, the force of the cork exploding from the bottle in one direction pushed the bottle backwards in the opposite direction. 
The experiment took some trial and error, but it was worth it.  =)

We tried it as the book said, by making a trough w/ aluminum foil to hold 2 tsp. baking soda.  We tried that a couple of times, but it would already be falling off the trough since the vinegar level was lower than the opening of the bottle; the mixture was already fizzing before we got the cork on.
So JohnDavid said to use the cut-off bottom of a sandwich baggie for the trough.  It was flimsy and hard to push thru the opening of the bottle.
After a couple of tries with the baggie, we dried the funnel and just poured in a heaping Tablespoon of baking soda, and corked it quickly.  You can hear my reaction!  And I even knew what was supposed to happen.

When it exploded, Abigail said, "Marty!"  She couldn't believe I'd be willing to make that mess in my kitchen.  Well, that's why I hadn't mopped yet, lol.  Then we went outside to try it again, since they wanted to throw it into the air.  It didn't explode in mid-air, but the reaction (of the cork/bottle AND of the kids) was the same.  They loved it!  With several failures, then finally a few successes, we used about half a gallon of vinegar.
This was yet another experiment that we only quit because it was time to go home.  And I was nearly out of vinegar!  =)




Inside: After the explosion, hear Abigail say, "Marty!"  She couldn't believe I let them do that!



Outside: This one went nearly the length of our house.
Abigail and Rebekah really got sprayed on this one!



Outside: This one hit the corner of the house.  (I did NOT think about the windows!!!)
And Rebekah was yelling, "No, dog, no!" to Levi just as I stopped recording.  =)





Newtons second law was not quite so interesting, but we did discuss it a little. The force of an object is equal to its mass times its acceleration.  Force = (mass) · (acceleration)  I did read page 245 several times, heh heh.
On the On Your Own question 10.6, I didn't understand how a toy car rolling north would have an acceleration to the south.  My email answer from Apologia said, "When you have a velocity to the north and an acceleration to the south then this means that the object is slowing down.  [and here I said, "duh!" smacking self on forehead]  With Force = Mass x Acceleration, notice that mass is the only term without a direction on it.  So the force will have the same direction as the acceleration.  Since this problem tells us that the acceleration is to the south then the force that is causing the object to slow down must be to the south as well."

Just in case ya wanted to know.  =)
Also see Example 10.2 at the end.  "... friction always opposes motion."