Tuesday, September 13, 2011

Co-op Science Week 3

This week we started talking about Isaac Newton, discussing his first law.

I introduced the concept by saying that Aristotle thought there must be force to have motion, but it appeared to him that the force must continue for the motion to continue. I demonstrated while talking by pushing a Barbie car across the carpeted floor, which came to a stop due to friction, of course. The kids totally understood, and could envision what would happen if we put the Barbie car on an ice rink, which would have less friction, which is what Galileo also figured out (well, not a Barbie car on an ice rink, but the idea that circumstances could exist in which other forces didn't slow the object down).

I'm having them write out a simplified version of each law, so for this week they copied off the board:

"An object at rest rends to remain at rest.
An object in motion tends to remain in motion in a straight line at a steady speed."

I demonstrated various activities that showed the concepts, also introducing them to the word "inertia". For a body at rest staying at rest we:

Put an index card on a glass, put a quarter on top of the index card, then flicked the card away. The quarter plopped into the jar with a satisfying plink. I also tried doing the same with glass bottles and dice, but couldn't get it to work there -- it had worked at home.

Stacked quarters, then flicked a quarter at the bottom of the stack and thus moved the bottom quarter of the stack. I couldn't do this at all, but one of the girls (who happened to come into the room early while I was setting up) was a champ, and could exchange quarters that way -- I had her demo this trick.

I also asked if they'd ever done that thing with the coins where you stack them on your elbow and then catch them with your hand when you drop your elbow. We used to do that when I was their age; one of the kids knew what I was talking about.

And, OF COURSE, I put a book on a piece of fabric on the table, then whipped the fabric out from under the book ... then tried it with a plastic plate ... then, yes, a breakable dinner plate with silverware and a glass (didn't put any liquids in the glass, instead using a beanie baby to add weight). This was by far the most popular demo. I tried it with a towel and the beanie baby, figuring the friction would send the animal flying, but, hey, it worked just fine.

Then I had the kids try whatever they wanted of these demonstrations at various stations in the room.

Afterwards they were to draw a picture of or write a couple of sentences about whichever activity they wanted to remember. I wrote titles for each on the board (some of the 3rd graders, especially the boys, seemed to be cringing at the concept of having to write, so I think having them copy my words as desired is just fine).

Moving on to a body in motion staying in motion, I spun a hardboiled egg and a raw egg. We looked at how fast I could get them to spin, and how quickly we could get them to stop. We discussed why. Some kids got it immediately (liquid inside the raw egg), some didn't.

We bashed the Barbie car into the wall and watched Barbie, Ken, and Kelly fly out of it. One of the girls was a pro at this, apparently having much experience with this concept at home -- she knew just how to place the dolls for the maximum effect.

Went outside and ran past a target on the ground dropping tennis balls on it, seeing if we could hit it, sort of like old bomber pilots trying to bomb a target (yelling "use the force, Luke!" was optional). The kids took turns doing this, with the others supposedly observing from the sidelines. One of them likened it to the car -- "the tennis ball stays in motion forward just like the dolls in the car stayed in motion." Wow, that's was an excellent way to describe what he saw!

After that we had about 10 minutes left, it was a glorious day, they'd been in various classes for 2 hours, so I said they should go to the playground and maybe explore forces there on the slides and all. Or whatever. Mostly they should run and yell and have fun before their next class.

I collected all of their papers so they didn't get lost. We'll make booklets of Newton's Laws which we can display at the open house later this fall.

1 comment:

Tara said...

I stopped blogging for a while, so I haven't been keeping up with all the great things you usually do. I was asked to teach someone to knit and remembered the fantastic class you gave some time back; am hoping to borrow some of your ideas, if you don't mind. Looks like your homeschool is full of wonderful learning, as always.