Hands-on Science and

Engineering at Pasadena

Public Library

Oct. 29, 2014

Energy cannot be created or

destroyed; it can only be converted

from one form to another.

• 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!!

Build a propeller-powered balloon helicopter!

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!