Tuesday, November 4, 2008

Class Novermber 4th

In today's class, we talked about specific heat, and thermal energy. I found Dr. E's lecture to actually be interesting because it was a topic I could understand and relate to. We learned that thermal energy is the total of all the kinetic and potential energy of all of the particals in a substance. (more mass = more heat)(as kinetic energy increases- speed increases)(as potential energy increases-separation increases). We also learned that heat is the flow of thermal energy from one object to another. Heat always flows from warm to less warm objects. I learned that when talking in scientific terms, one is never to say "colder." One is to say "less warm." Then we talked about the rate of cooling. The rate of cooling of an object- whether by conduction, convection, or radiation- is approximately proportional to the temperature difference between the object and its surroundings. Rate of cooling is also known as Newton's law of cooling. An example of this is holding an ice cube in your hand. After a while, the ice cube will melt because the heat from your hand transfers to the ice cube, while the coldness of the ice cube transfers to your hand, in turn cooling down your hand. Another example is holding a cup of coffee in your hand. The cup of coffee will eventually cool off while your hand will get very hot because the cup of coffee is warmer than the temperature of your hand. Overall, an interesting and informative class session!

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