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.

Inquiry Projects - a hands on approach to the scientific method

On of my main goals in my 7th grade science class is to expose students to the scientific method and get students doing their own experiments.  No matter how many time I work on things like variables, controls and constants, it's hard for students to understand these concepts without some hands on experience.  Two or three times a year I have students complete, what I call, an Inquiry Project.  In this project, students get the opportunity to develop their own problem/question to investigate.

I help students to develop a problem/question and then they are to write the hypothesis, procedures and materials by themselves.  In addition, I provide them with some analysis questions asking things about variables and constants.

Below are some pictures of some of the activities that my students were conducting.

How does the amount of baking soda effect how much carbon dioxide is produced when mixed with vinegar?

How does the number of mentos effect how big the explosion is when mixed with diet coke?