Energy+Transformations

=ENERGY KIDS-Website= = = = = =TYPES of energy transfers...= ==

=Learning Opportunities:= //Note: Parts of the following are edited from NSTA Scipac//

Here are another couple of examples of how we can follow energy until it shows up as thermal energy.


 Figure 2.7. Energy transformation as a person shoots a paper wad at an aluminum can with a rubber band.  ==Obviously, energy transformations can get a bit complicated. Even simple ones, though, can pose a mystery. Why does the washer on the string—a pendulum—slow to a stop? Where does the energy go? For a clue, get a paper clip and start bending it back and forth for a while. Then feel the spot where you were bending it. Hot, huh? The friction within the paper clip transforms kinetic energy to thermal energy. The pendulum is similar—as the pendulum moves, the string is bending where you hold it, just like the paper clip.== ||  ||
 * [[image:http://scipacks.nsta.org/lcms_prod/evsfiles/themes/thumb_clear.gif width="1" height="7"]] ||
 * ||  || ==In the beginning, all of the energy resides in the rubber band, which has because of its stretched shape. When let go, the rubber band imparts kinetic energy to the paper wad. The rubber band itself moves, so we have to include that kinetic energy. It also makes a sound, so we also have to include the kinetic energy of the air molecules that accounts for the sound. In the process of moving, the rubber band and paper wad hit air molecules and impart energy to them, so that’s also in the diagram. The paper wad hits the aluminum can and imparts kinetic energy to the can. In the collision, both the can and paper heat up just a bit, and all that energy eventually becomes thermal energy of the surrounding air molecules.==



Figure 2.8. String and washer pendulum. 
 * [[image:http://scipacks.nsta.org/lcms_prod/evsfiles/themes/thumb_clear.gif width="1" height="7"]] ||
 * ||  || So, while the pendulum is going back and forth between gravitational potential energy and kinetic energy, it constantly loses energy to thermal energy. See Figure 2.9. ||   ||

Figure 2.9. Energy transformations of a string and washer pendulum.

**Click on the site below to play the game "//__Welcome to Energy ville__//"** This is a game where you will be making some critical energy decisions for a city of the future. Lots of fun! This game along with your journals should be discussed with one or more classmates. Let the teacher know when you are ready to discuss with a classmate.

Use the following questions for "accountable talk" when discussing with your group: 1. How did monitoring your progress affect the decisions you made? 2. What required the most energy to power? least? 3. What surprised you most about the energy cost, environmental impact and security? 4. How did your decisions change from level 1 in the game to level 2?



Welcome to Energyville

= =

= =

= =