Newton's Third Law and some fun

This past week I brought out some Newtonian Demonstrators aka Newton Balls aka the click clacky things.  The students love playing with them so it's a great hook to get them into this lesson.  I used these to demonstrate Newton's Third Law.  Students say that every action had an equal and opposite reaction.  Each time they lifted one of the balls on one side and let it go, a ball went up, just as high on the other side.  Most students expected this to happen, but getting them to explain what was happening in terms of Newton's Laws.  It was fun to have students predict what would happen when one ball was lifted on one side and two balls was lifted on the other side.  Most students were amazed with what happened as it wasn't what they expected.

Of course, with some fun comes some problems.  As you can see the demonstrators often get tangeled.  Most of them I am able to get out in a few minutes, but the one below was a real challange.  It was a little worse before I took that picture, but I got a little bit out.  I tried for TWO days and couldn't untangle it (and I like to think that I'm good at untangling things).  One of my honors 8th graders, who isn't even in the class that I did this in) was able to get it out.  I was truely amazed!

You can download a copy of this activity.