TESLA Balance and Motion 2011 Balancing Pencils Lesson 2

The Big Idea of this Investigation Our physical world is governed by the properties and interaction of objects and how force affects motion.

ENGAGING SCENARIO The Lewiston Toy Company likes the information you have written in your science notebooks about toys that balance. They would like for you to test one more model that they think will help make some good balancing toys. They have sent us some materials and printed information that may help us. They also need us to continue to keep accurate records and labeled drawings in our science notebooks so we can report what we found out in a couple of weeks. What is the problem we need to solve? What do we need to investigate? The Lewiston Toy Company likes the information you have written in your science notebooks about toys that balance. They would like for you to test one more model that they think will help make some good balancing toys. They have sent us some materials and printed information that may help us. They also need us to continue to keep accurate records and labeled drawings in our science notebooks so we can report what we found out in a couple of weeks. What is the problem we need to solve? What do we need to investigate?

Kit Inventory What color/shape is the object? Where have you seen this object before? What do you think we will use this for in the unit? What color/shape is the object? Where have you seen this object before? What do you think we will use this for in the unit? These are the objects that have been sent to us by the Lewiston Toy Company. I have put them in this large bag. Let’s see if we can identify them.

Here is the new model the Lewiston Toy Company sent us to test. It looks like an arm that is holding on to a pencil. We need to use the knowledge from our last lesson to balance the picture on a craft stick. Our goal is to make the picture balance on the pencil point. What is a stable position? Where should we place counterweights to balance an object and make it stable? Now lets see if we can find a way to balance the picture on the pencil point.

Making Meaning Conference Can you make a stable system with no clothespins? One? Two? Why? Where did you put the clothespins to make a stable system? Now the Lewiston Toy Company has a greater challenge for us. They are really hoping you can find a way to make a real pencil balanced and stable on its point. In addition to our clothespins, the Lewiston Toy Company has sent us some flexible, aluminum wire that may help us solve our problem, but remember… Is an object balanced if it is attached to the craft stick?

Focus Question (What is the problem?) How can we use clothespins and aluminum wire to balance a real pencil on its point? NOTEBOOK ENTRY Discuss with your group of scientists a possible focus question for this investigation. Prediction (related to the focus question) I think that if we ___________________________________, the pencil will balance on its point on a craft stick. I think this because…

Solving our Problem Scientists always try to make careful observations. NOTEBOOK ENTRY Test your ideas to see if you can solve the problem. If you think you found a way to balance a pencil on its point on a craft stick, make a drawing of your design in your science notebook. Be sure to label all of your drawings. Sometimes scientist like to record the ideas that don’t work because these ideas can also help us understand the problem.

Making Meaning Conference Were you able to balance the pencil without wire or clothespins? Does it matter where you put the wire and clothespins? How were you able to make the pencil balance on its point? How could you balance a fork on its point on a craft stick? How could you balance a paper cup on a tight string? What is a strategy for balancing an object on its point?

Claims and Evidence Use your own words, or words from the word wall, to help you complete the following sentences in your science notebook. I claim that to balance a pencil or other object on one point, ___________________ need to be added __________ the balance point. I know this because… NOTEBOOK ENTRY

Reflection/Conclusion Revisit your original prediction and respond to one of the following stems: My prediction was accurate or was not accurate because….. I wish to revise my prediction because… My original thinking has changed because… What did you learn…? What really surprised you…? What new questions do you have…? What would you like to know more about…? NOTEBOOK ENTRY