demoTK1 meetingMeeting 10

Balloon Hair Static

Three related teacher demonstrations: Balloon Hair Static, Balloon Pulls a Can, Balloon Won't Inflate in Sealed Bottle.

Teaching & key ideas

1. Balloon Hair Static Materials: Balloon; wool/fleece or hair What you do: Rub balloon and hold it near hair or tissue bits. What students see: Hair stands up or paper jumps. Question: How can the balloon pull without touching? 2. Balloon Pulls a Can Materials: Empty aluminum can; balloon; fleece What you do: Charge balloon and hold it near a can on its side. What students see: The can rolls after the balloon. Question: Why does the can follow? 3. Balloon Won't Inflate in Sealed Bottle Materials: Plastic bottle; balloon; bottle with/without small side hole What you do: Try inflating a balloon inside a sealed bottle, then open a small vent hole. What students see: Balloon is hard to inflate until air can escape. Question: What is stopping the balloon?

Lesson flow

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: How can the balloon pull without touching? Question: Why does the can follow? Question: What is stopping the balloon?