Thursday, January 5, 2012
This week, Walker was in charge if the lesson for preschool, and I think he did a great job. We learned about pulleys!
First, the four big kids tried to lift Moira's new red wagon with just their hands, but could not do it.
Then Walker hooked the wagon up to the single wheel pulley outside of the kitchen playroom, to see if they could lift it with that. Nope.
That's when the block and tackle pulley (in the first picture) came out. Each additional wheel in your pulley makes it easier to lift things, so with these six wheels, tada!
The four big kids (plus the occasional help from David) were able to lift the wagon. They could have gotten it higher in the air, but they ran out of horizontal space.
Then they tried two at a time, and were still able to lift it up the same amount. We didn't suggest that they try one at a time, although I think that might have worked.
Walker's original plan was to have them lift *him* with pulleys, but Moira couldn't lift more then 10lbs on her own when he was figuring the lesson out, so he didn't think it would work. Given that two of them could lift the whole wagon, I think it might have. We may have to revisit this when everyone's muscles are bigger.
I found Pull, Lift, Lower by Michael Dahl at the library, which manages to be informative without being too long for the 3-4 year old set, although sadly it doesn't mention that bikes and motorcycles also work with pulleys.
All in all, this lesson was pretty cool. I need to remember to plan more full body lessons. It's so easy to default to arts and crafts, but the kids have loved the physical lessons we've done.