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Balloon Drive Design Challenge. Problem. Make a Mylar balloon hover (neutrally buoyant) Neutral buoyancy is when the force pulling down ( gravity ) is equal to the force floating up ( lift ), so the balloon doesn’t move up or down. . Materials. 1 helium filled Mylar balloon Paper
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Problem • Make a Mylar balloon hover (neutrally buoyant) • Neutral buoyancy is when the force pulling down (gravity) is equal to the force floating up (lift), so the balloon doesn’t move up or down.
Materials • 1 helium filled Mylar balloon • Paper • Paperclips • Tape • Cardboard or Card Stock
Brainstorm • How can you stop a balloon from floating upward? • How will you know when your balloon is neutrally buoyant? • Once your balloon hovers, how can you move it?
Design and Build • Make your balloon hover. • To do this, you must balance lift and gravity. • When it floats in the same place for about 5 seconds, you’ve done it!
Test • Explore air pressure –Use a piece of card stock to drive your balloon. • What moves your balloon best –One stroke right next to the balloon? Big swoops? Fanning? Quick swipes? • Hint: When you sweep the cardboard beside the balloon, you temporarily remove some air. Other air nearby rushes in to fill the space, carrying the balloon with it.
Make it move! • Design an obstacle course for your balloon! Drive the balloon up and over or in between objects – chairs, tables, or a friend!
Inside the Engineering • Balloons drift wherever the wind takes them. But if you add a way to control where the balloon goes, say by adding an engine, you’ve engineered a blimp!
Problem • Make a blimp and a jet-propulsion system so that a blimp flies straight and far under its own power.
Materials • Two Mylar balloons per team • Paper • Tape • Balloon Pump • Scissors • Straws • Latex Balloons
Make a Blimp • Make a blimp by rolling up a piece of paper and connecting it between two Mylar balloons. • Make your blimp neutrally buoyant.
Make a Jet • Fit a straw into the balloon’s neck. Seal it tight with tape.
Brainstorm • Where would be a good place to attach the jet to the blimp? • How will you inflate the balloon?
Build, Test and Redesign • Attach and test your jet blimp. Does it fly straight and far? If not redesign your jet blimp until you are satisfied with the results.
How is your Blimp Jet an example of Newton’s Third Law? • Watch: • http://pbskids.org/designsquad/video/video_download.html?suffix=none&clip=s3/DS_301_04&title=Thrust%20and%20Newtons%20Laws • http://pbskids.org/designsquad/video/video_download.html?suffix=none&clip=s3/DS_303_03&title=Newtons%203rd%20Law