It was another one of those "hundred times a day" moments, though this one a little more detailed than most.
Hunter was desperately trying to figure out how to trim his own nails, but had his finger that he was trying to push with far too close to the end, and as such they weren't clipping. He told me that they weren't sharp enough, and when I looked at him and saw the way he was holding them, I explained that the reason they weren't working was because he didn't have enough leverage.
Which lead to a whole discussion on leverage, fulcrums, force, and even inertia. I grabbed a yard stick, a shoe, and a heavy book, slid the yard stick under the book and had Hunter lift it with just one finger right beside the edge of the book. Then, with the fulcrum in place (aka shoe) and us using the far end of the stick, we experienced the power of leverage.
He thought this was pretty cool.
I actually had to get out my handy science homework helper to remember what it was that a fulcrum was called [which I love and use all the time, but sadly discovered that it is out of publication so I can't post a link].
On the same page as different kinds of levers, we talked about how a lever was a kind of machine, and that force was a push or a pull. He wanted to try out his lever (which he had now turned into a seesaw) on one of his toys, flinging it into the air. I then mentioned that the toy didn't have very much inertia, which is how much force it takes to set it into motion. I explained that anything can be set into motion if you apply enough force, and talked about how we could even move the wall or house if we applied the force of a bulldozer.
I asked him what else in the room had a lot of inertia, and he said the table. We categorized a few more things by their amount of inertia, then he went back to flinging his action figure.
I wrote up some vocabulary cards for him (force, machine, lever, motion, fulcrum, and inertia) but, instead of quizzing him on them, I joined in his play and decided to use the words in context."Go ahead and apply force to the lever, if it's a big push the dog will be set in motion really fast." "Let's see what happens if we move the fulcrum this way..." and "Which one to you think has the most inertia: the dog or the man?"
Then it was time to go to bed. When I woke up this morning, there he was, in the living room, experimenting with force and motion and simple machines. And also turning the yard stick into a bridge for his soldiers to attack the bad guys.
"My foot standeth in an even place: in the congregations will I bless the LORD."
Psalm 26:12Hunter is 4 years, 9 months old