An earthquake shake table is a small model that lets students test how buildings move during shaking. In this project, two boards, four tennis balls, rubber bands, and a ruler create a simple table that slides back and forth like moving ground. Marshmallow and toothpick buildings make it easy to compare different shapes and supports.
This matters because engineers study shaking to design safer buildings, bridges, and schools.
Key Facts
- Earthquake shaking is side-to-side motion that can push and pull a building at its base.
- A wide base usually improves stability because it lowers the chance of tipping.
- Triangles are strong shapes because they do not change shape easily when pushed.
- Bracing adds diagonal supports that help a structure resist sideways forces.
- Speed = distance / time, so a shake table moved 20 cm in 5 s has speed = 4 cm/s.
- Fair test rule: change only one building feature at a time, such as height, base width, or bracing.
Vocabulary
- Shake table
- A device that moves a model back and forth to imitate the shaking caused by an earthquake.
- Seismic
- Seismic means related to earthquakes or vibrations traveling through the ground.
- Base
- The base is the bottom part of a structure that supports the rest of the building.
- Bracing
- Bracing is extra support, often diagonal, that helps a structure resist bending, twisting, or collapsing.
- Variable
- A variable is one part of an experiment that can be changed, measured, or kept the same.
Common Mistakes to Avoid
- Changing more than one building feature at a time makes the test unfair because you cannot tell which change caused the result.
- Pulling the ruler with different strength each trial gives uneven shaking because each building is not tested under the same conditions.
- Building only tall, narrow towers can make the models tip too easily because a small base gives less support during side-to-side motion.
- Forgetting to record results right away can lead to guesses because details like wobbling, broken joints, and collapse time are easy to forget.
Practice Questions
- 1 A student pulls the top board 12 cm to the right and then releases it. If the table moves 12 cm in 3 seconds, what is the average speed of the table in cm/s?
- 2 Two marshmallow buildings are tested. Building A is 18 cm tall with a 6 cm wide base. Building B is 18 cm tall with a 12 cm wide base. Which building has the wider base-to-height ratio, and what is each ratio?
- 3 A tower with square sides collapses quickly, but a similar tower with diagonal toothpick braces stays standing longer. Explain why the braces help during shaking.