Friday- January 11,2008- Day 81
On Friday, we started class reviewing Thursdays key message. The key message was the work-energy relationship. Work=force times distance=change in total energy. The equation is on your reference tables. Et=KE+PE+Q, then W=change in PE+change in KE+change in Q. The change in Q=Heat added to the system (work done against friction is lost as heat).
Next, we did a problem workshop consisting of groups of three maximum. These groups reviewed problems from worksheet number five, which was using solutions as a guide. This carried on for about fifteen minutes as Mr. Wirth went around and answered all the questions people had.ANother activity that took place during class was when Mr. Wirth explained elastic potential energy. This is when work is done in compressing or stretching a spring. Elastic potential energy is stored in the spring. As Mr. Wirth showed a very large spring compared to a tiny one, Paul Cooney noted that, "You can launch a baby off that!" There was a graph that is viewable on the notes that explains the force vs. elongation within elastic potential energy. As force increases, so does elongation. The elastic PE equation is PEs=1/2kxsquared. PEs is the elastic potential energy stored in the spring. There were four example problems that were given and reviewed. A schedule until January 16, 2008 was also given. The ticket out the door included an example from your own experience of the exchange of Kinetic Energy, Potential Energy, and Internal Energy, as well as to explain where the energy comes from and how it changes form. Homework: Blog status and worksheet number 6 on Elastic PE, which is due Monday