Wednesday, March 5, 2008

3/5/08 scribe thingy


So today we took a lot of notes….

Today started off somewhat exciting with a four minute video about Benjamin Franklin. Nobody really understood what happened in the video because everyone was playing Frisbee, to be completely honest. We then talked about matter as a source of electricity. Matter is composed of atoms which are composed of neutrons (neutral charge), protons (positive charge), and electrons (negative charge). Neutrons and protons are located in the nucleus of an atom and the electron orbits the nucleus. We finished with matter and went into what a Coulomb is. This is a scalar quantity and 1 Coulomb = 6.25 x 10^18 elementary charges and one elementary charge = 1.60 x 10^-19 C. After that, we figured out the reasoning behind how an object becomes positively or negatively charged. This happens when there is either an excess or a deficiency of electrons. The way an object becomes electrically charged is by gaining or losing electrons which all depends on the tendency of the material. We also did a demo on how to attract a neutral object. Mr. Wirth showed it was possible by rubbing a balloon on his head and then sticking it to the wall and showing us that it would stay where he left it. We then took a look at an electroscope. This is a device that determines the presence of an electrical charge and whether it’s positive or negative. Finally, we learned that there are ways to remove or add electrons to neutralize the static charge which is called grounding. Some examples of this are grounding straps and lightning rods. The End

2 comments:

Laura K said...

nice post kevin, very informative.

Bryan said...

3/6/08 It won't let me create my own post

In class we talked about the conservation of charge. The total charge in a system remains constant, and cannot be created or destroyed. The charges in each system however can be transfered from one object to another. We learned the equation Q=ne. Q is the total charge on the object(in coulombs), n is the number of elementary charges, and e is the elementary charge.

For example, A balloon has aquired a charge of -3.20x10 to the -17 coulombs. Q=ne. -3.20x10-17=n(1.60x10-19C). n= 200 2xcess electrons.

We also talked about charging by induction. The method of charging is called charging by induction. We induced a charge separation, the grounded one region of the charge.

Last, we learned about Coulomb's law. Coulomb's law is similar to the behavior of the law of universal gravitation. The electric force between two point charges is directly proportional to the product of the charges, and inversely proportional to the square of the distance between their centers.