When I was making some general plans for my last month at my current job, I was thinking about fun. I was thinking about doing stuff that I hadn't done with kids before; I was thinking about really taking the opportunity do things that are truly engaging, and encourage experimentation and exploration.
I'm not sure where the idea came from (but I've seen it since over at Teacher Tom); but when the thought of having a pendulum available popped into my head, I couldn't ignore it. We spend so much time reminding children not to knock over other people's buildings that a few days of knocking things down on purpose seemed right up our alley.
There was a bit of a learning curve for me: I set the pendulum up, wrapping the string around a light fixture. I had to rethink it a bit as we went along, eventually providing a table for the stacking of the recyclables. The building process takes so long, and the knocking down is so quick, that it seems a bit unbalanced.
There was an initial fascination with the recycling ("Ooooh, I love these! Yum!" and, "Wow! Who ate this? Is this for snack?!?!?!"). There was careless stacking and less than ideal choices for positioning, and I found myself scaffolding here a lot. But it added another layer to the work: Which box seems strongest? Will this bottle ba able to hold this larger box, or will it fall? I modeled using the "stronger" pieces on the bottom of the stack and putting the more delicate things on top. Sometimes the stack wouldn't totally tumble, and we talked a lot about making stacks that the pendulum could not beat.
The ball was pinned up during the stacking process, and it did necessitate having a teacher there to unpin it. I thought that was helpful on the first day - it also prevented throwing the ball and children being in the way of the extra eager physicists. Being with them allowed me to scaffold in the building process. I have mentioned before that we don't have unit blocks (only cardboard blocks), so this is not a common experience for this group.
There was so much delight on the children's faces then that stack would fall, and they wanted to do it over and over and over again. They let others in and took turns releasing the pendulum. They talked about their favorite foods. They spotted each other when one child would be standing on a chair to put a paper tube all the way on the top. It was so much more than physics!