Monthly Archive: January 2015

Jan 31

Vertical wind tunnel and patterns in ping pong balls

Carlin used a shop vacuum exhaust and concatenated translucent 3-liter soft drink bottles to form vertical wind tunnel to illustrate balance between aerodynamics and mass.  Videos show patterns in floating ping pong balls using high speed capture.  First video is with 3 ping pong balls and second with 15.  Balls were striped in different colors …

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Jan 31

Energy harvesting from soccer ball

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Max is using piezo-electric transducers to convert the energy from kicking a soccer ball into electricity, potentially useful for lighting or cellphone charging. Piezos produce high voltage and low current in one polarity when flexed and then in the reverse when the flex is reversed to return the piezo crystal to a neutral position.  To capture …

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Jan 25

Build an earthquake-safe structure

ready for judges

2015 April 26 Day of the competition! Team 476 Gravity Rex gathered at the Tech Museum of Innovation with our building and engineering journal to compete with thousands of other kids and face a panel of judges. Our engineering journal was pronounced “good” as we could back up everything we claimed about our building and the …

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Jan 13

Winding our own electromagnet

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Max brought several electromagnets he made himself as well as wire and cores to make another.  His project to capture energy from soccer balls being kicked will use an electromagnet as part of the kick-testing jig, so he wanted to make a more powerful one. We measured voltage, current, and pull strength for an existing …

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Jan 09

Newtons Cradle spin

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Our Newton’s Cradle nears completion.  We are discussing how to secure the cords suspending bowling balls to the saw horse.  In the time we had, we spun the bowling balls.  See the balls behave like gears and also climb up their suspension cords: We inverted a honey jar and observed the speed of air bubbles, large and …

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