Art of Construction

Unit 15: Balloons...and Back to the Tent

tension in a balloon

"If you blow up a sausage-shaped balloon, it becomes stiff. The internal air pressure acts against the wall of the balloon in all directions so that its cylindrical shape stretches and is tensed both lengthwise and crosswise."

p. 135 Art of Construction
balloon as a column, click to see an animation
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"The balloon will be capable of acting as a column and of supporting a certain amount of load. This is because the load tends to compress its longitudinal walls, but these, thin as they are, will not buckle and collapse until the compression due to the load cancels the tension due to the internal air pressure. You can prove this by putting a cup on top of the balloon and loading it with a number of small books or a small glass that you gradually fill with water."

p. 135 Art of Construction

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Unit Navigation Unit 1: From Cave to Skyscraper Unit 2: Building a Tent Unit 3: What is a Beam? Unit 4: What Do We Build Structures With? Unit 5: The Floor of Your Room Unit 6: A Steel Frame Unit 7: Part of a Building You Don't See Unit 8: What Tornadoes, Earthquakes, and Temperature Can Do Unit 9: How to Fight Tornadoes and Earthquakes Unit 10: Ropes and Cables Salvadori Center Unit 13: Shape and Strength Unit 14: Barrels, Dishes, Butterflies, Bicycle Wheels and Eggs Unit 12: Strings and Sticks Unit 11: Sticks and Stones Unit 15: Balloons...and Back to the Tent