Unit Blog

Physics Blog

1. This unit began with learning about charges. There are two types of charges, negative(or electrons) and positive(protons). Opposite forces attract whereas negative forces repel each other. There are three ways to charge something. YOu can charge something through direct contact, friction and induction. induction is way to charge something without direct contact. In this section we answered an important question: Why does your hair stand up after putting on a sweater. The answer is that the sweater steals electrons through friction. So the sweater becomes negative and the hair becomes positive. Because the hair is positive and wants to repel each other it will stick up and repel the other pos charge hairs. We then went on to learn about Polarization. There are a few important vocabulary words to be familiar with. Conductors-let charges move through the object and insulators-stop charges from moving. polar- charges separate from each other. There is an important law in this section, Coulomb's Law. This law states that the force between any charges in inversely proportional to the distance. Therefore the larger the distance the less force.     F=K q1 * q2 /d^2. This is the complete answer to why plastic wrap sticks to the bowel. 1. Plastic Wraps is charged by friction and when brought near the bowel the bowel polarizes. 2. The positive charges in the bowel move close to the negative plastic wrap and the negative charges move away from the plastic wrap.  3. The distance between the opposite/ attractive charges is smaller than the distance between the like/repelling forces. 4.  F=K q1 * q2 5. Since there is a greater distance between the repulsive force the force between them will be less than the attractive forces. 6. Thus, the plastic wrap sticks to the bowel. The next section was electric fields and shielding. An electric field-area around a charge that can influence(push/pull) another charge. The arrow in the fields represents which way the positive charges will pull. also the closer the lines are together--the stronger the electric field. sensitive electronic devices need to be in a metal container so the charges are not pushed or pulled anyway. Electric shielding- inside metal container changes with the distribute evenly, no force. We then learned about electrical potential energy. Electric potential- pulling opposite charges together potential to repel away or build up potential energy between attractive charges. electrical potential is the electric potential energy/charge. We then went on to learn about voltage and current. Current is the flow of electric charge. voltage is electrical pressure or a measure of electrical difference. resistance is the resistance of a material to the flow of electrical charge. difference in voltage is the same as the difference in electrical potential. if there is more resistance there is less current. Therefore a thing long wire has less current and a high resistance whereas a wide short wire has more current and low resistance. you must have voltage (electric potential) difference to cause a current. voltage=potential energy/ charge. We then learned that a power company does not give you electrons but rather we pay for energy. There are two types of current. AC-or alternate current is seen in an outlet in a wall. and DC-or direct current which is seen in a battery. The reason a light is so quick to react is because of the electric/energy signal because electrons move slowly. We then learned about series and parallel circuits. in a series circuit the current remains the same when you add another lightbulb. whereas in the parallel circuit the current is greater. In a series circuit the resistance is greater when adding a lightbulb in series and the same when adding a lightbulb in parallel. If you unplug one appliance that is wired in parallel the others will still remain on whereas if you unplug one in series every other one with turn off. 

 My effort towards class is pretty consistent and I feel that I am a persistent participant. I also go in early when I feel that it is necessary. And my effort is reflected in-group work especially, which is a time that I am fully involved with the activities. I do my homework every night.  By going in early and asking questions in class I feel that I have strong communication. And my creativity was reflected when making the podcast, and how my partners and me would use real life examples and then further discuss them. My goal for the next unit is to make sure I study before each quiz and go in early to be tested on my knowledge of that particular unit. The connections I make with everyday have been pretty obvious in this unit. This so is because we have been discussing how lightbulbs work and how you get power in your house. Also we learned the answers to important questions such as why your hair sticks up when taking off a sweater and why people use dryer sheets.