# Pratt School of Engineering, Duke University

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Learners design and create musical instruments from common objects; their challenge is to create an instrument that can make three different tones.

\$1 - \$5 per group Ages 8 - 14 45 to 60 minutes
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Learners work in groups to design and build a tower out of balsa wood. As a motivator, they can compete to build a tower with the highest strength-to-weight ratio.

\$5 - \$10 per group Ages 11 - 14 1 to 2 hours
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Learners initially test to see how many drops of liquid (water, rubbing alcohol, and vegetable oil) can fit on a penny.

\$1 - \$5 per group Ages 11 - 14 10 to 30 minutes
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Each learner chews a piece of gum until it loses its flavor, and then leaves the gum to dry for several days.

\$1 - \$5 per group Ages 11 - 14 2 to 4 hours
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Learners apply their knowledge of heat transfer to design two cans - one that will retain heat and one that will cool down quickly.

\$1 - \$5 per group Ages 11 - 14 45 to 60 minutes
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Learners use engineering design principles to construct and test a fully solar-powered car. Solar car kits usually include a photovoltaic cell and motor; some include a chassis as well.

Over \$20 per student Ages 11 - 14 2 to 4 hours
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Historically, sea floor mapping (bathymetry) was done by soundings.

\$1 - \$5 per group Ages 11 - 14 2 to 4 hours
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Learners use a spring scale to drag an object such as a ceramic coffee cup along a table top or the floor.

\$5 - \$10 per group Ages 11 - 14 45 to 60 minutes
Source Institutions
Learners design their own experiment to determine conditions that either help or hinder the decomposition of carrots by soil microbes.

\$10 - \$20 per group Ages 11 - 14 1 to 4 weeks
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Learners determine the surface area and volume of two identical boxes, and then figure out the dimensions of a cubical box with the same volume.

1 cent - \$1 per student Ages 11 - 14 2 to 4 hours