propeller powered balloon helicopter: curiosity machine hands-on science class at pasadena public...
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In our last class of a four-week session called "Curiosity Machine" at Pasadena Public Library, we made balloon helicopters with an elastic motor designed from boba straws, washers and rubber bands. We learned about elastic potential energy.TRANSCRIPT
• Potential Energy is the energy possessed by an object by
virtue of its position or condition
• Gravitational Potential Energy is the energy of an
object due to its position in a gravitational field
• Elastic Potential Energy is the potential energy stored
when something is stretched or deformed
• Kinetic Energy is the energy possessed by an object by
virtue of its motion
• Mechanical Energy is the total energy in a system, the
total kinetic energy and potential energy stored in an
object
http://physics20project.weebly.com/unit-4-work-and-energy.html
The bow and arrow is one of the
first tools humans made to use
elastic energy to do work.
The farther you pull on the bow,
the greater elastic potential energy
you store.
Also, pulling on the string of a bow
changes its shape, which increases
its elastic potential energy.
When the arrow is released, elastic
potential energy converts to kinetic
energy and the arrow flies!
Can you name some other examples of elastic
potential energy?
Balloons expand when you fill them with air, but if you give the air an
opening through which to rush out, the balloon will contract, also moving
away from the direction of airflow. Energy!!
Torque = Force x Distance from the fulcrum, so when
you’re designing the blades of your helicopter, keep in
mind that longer blades will produce more torque,
which will store more elastic potential energy and
power your helicopter longer!
Cut blades out of paper plates (or another material if
you want) and attach them to either end of an unbent
paperclip. Then pull a rubber band around one of the
blades so that it hangs right in between them over the
paperclip.
Next you will use your skewer to push the rubber band
through your boba-straw-and-washer motor casing.
Stick the skewer through the rubber band where it
sticks out from the straw (cut your straw shorter if you
need to). Now you have created an elastic motor!
Attach helium balloons to the skewer, wind up your
blades, and let it fly!