http://pbskids.org/designsquad/parentseducators/resources/rubber_band_car.html
Rubber Band Energy
http://www.sciencebuddies.org/science-fair-projects/project_ideas/ApMech_p017.shtml
http://www.ncsu.edu/kenanfellows/kfp-cp-sites/motion-design/index-61222.php.html
http://www.brightstorm.com/science/physics/heat-and-thermodynamics/kinetic-and-potential-energy-of-atoms/
Kinetic and Potential Energy
Energy is defined as the ability to do work. When the work is actually being done, we term
the energy “kinetic.” When the work is waiting to be done, or when there is the potential
for work to be performed, we term the energy “potential.” Kinetic energy is the energy of
motion, potential energy comes from work having been done on an object which was then
stored. For example, a rubber band zinged from your finger has kinetic energy. While it was
stretched, waiting for you to release it, it had potential energy. The rubber band was stationary,
but work had been done on it to move it to its present position.
Now, we know that the farther we pull back a rubber band, the faster and farther it will
fly. Consider this situation in terms of potential and kinetic energy: When I pull back the
rubber band to a great distance, I am doing more work to it than if I pulled it back only
a small distance. More work means more energy is provided to and stored by the rubber
band. When I release the rubber band, it has more energy to move. More energy means
more work can be done by the rubber band. There is a connectedness, then, between
potential and kinetic energy for matter.
For moving objects, we can easily calculate kinetic energy using the formula:
KE = (mass x velocity2)/2 or 1/2 mv2
Although mass and velocity both have great effects on kinetic energy, it is velocity, more
significantly, that determines kinetic energy.
