Sunday, February 21, 2010

Energy Reflection

A. In this unit we covered the conservation of energy. We went over how energy can be transferred from one method of storage to another and that the total amount of energy does not change. There are several different methods of storing energy. The types are elastic, kinetic, potential gravitational, potential, chemical potential, thermal, sonic, dissipated and internal. The energy is transferred in three different ways. The first is work which occurs when an object is displaced, for example if a person pushes a desk across a room. The energy is transferred by the external force provided by the person. Another way energy can be transferred is by heating. This happens when kinetic energy transfers to a colder object from a warmer object. The third way energy can be transferred is through electromagnetic radiation. An example of this is a microwave heating up food; it sends radiation to the food, thus warming it up. The main form of energy transferred we went over was work.
There was some difficulty in this section. I found most difficult the amount of equations that could be used to come to the same solution. I found confusing that many different types were equal to others and some only sometimes. Sometimes I would have to try several methods before finding the one that actually got me the correct answer.

My goal was to figure out what equations made sense and should be used to solve each problem, but even if I used the needed equation I would get the wrong answer then I’d look for my error and discover I had either multiplied something wrong or had forgotten an important part of an equation. I would sometimes, but rarely use trial and error if the problem was tricky. Once I got the hang of it I no longer used trial and error but used the equation that corresponded with the problem and so I was able to solve the problem. The problems where I used trial and error were mainly the problems involving springs, or something that stretched, but once I understood them and knew what equations were need to determine certain factors, I no longer used that method. I am fairly strong at problems that involve trig in order to find the solution. I had trouble in memorizing all the equations and when I should use them.

B. I find that that the energy transfer is used all the time. One example is that while I am currently typing I am using kinetic energy to pushes in each individual key and that energy is then transferred to the keyboard, the cord it is attached to them to the usb port of my CPU and so until the energy is “displayed” on the screen. When the character is displayed on the screen, energy has not stopped working, nor will it ever. Electrons on the computer monitor impact the screen producing light and creating an image. The gravitational potential energy that occurs in this situation is measured in Joules, which are the units of energy.


  1. This is a really thorough reflection. Good job but just check your punctuation. Other than that you did very well.

  2. Several points to clarify or explain:
    1. What do you mean by: "force is transferred by the external force provided by the person"
    Are forces "transferred"?
    2. Explain your saying that: "emits electromagnetic energy and gains then gain kinetic energy"
    3. You devote a very large part of your reflection to discuss items that were NOT covered in the class. Radiation and Heating are not the "meat" of this unit plus there is no discussion of conservation of mechanical energy at all.

    Do you believe that the goal of learning physics is just to "find the right equation"?
    Or is it more important lo understand the concepts?
    How can trial and error be an effective way of solving problems?

    Your different applications are not explained clearly. Better stick with one application and explain it in detail.

    Your statement that "This type of energy is measured in Joules which is a type of gravitational potential energy." is incorrect. Are you saying that Joules are a type of energy? Aren't these the units of energy?

    You need a MAJOR re-writing of your reflection.

  3. Daniel-
    Over all it was an okay post however, there are several things for you to address. First, Joule is not a type of energy, it is the unit. Also I found this confusing because we did not learn the majority of this in class hence why I was so confused my last comment. I think that if next time you stick to what we did in class it would be much clearer. Also please check for word repetition (:

  4. Your reflection is improved however you did not discuss what conservation of energy is.
    Your application is not clear, there is energy in the capacitors in each of the keys that creates an electric current. This is material that we did NOT cover in class so you should have done good research on it.