The Birth of Physics!

After a long and hot summer, we are all finally back to school and ready to learn learn learn! Each year, the work gets more challenging and requires more of your time to understand the concept being taught. This year in Physics class, we have started out by creating a personal blog in which we keep track of the material we learn in class. Blogs are great ways to review what you have already learned, especially when it comes close to a test or exam. I am very excited to start out the year like this, and am hoping for a wonderful experience in Physics class with Mr. Chung ! Hopefully we all learn fascinating things about physics, because I am so excited to get started.

This is indeed my first blog entry since school has started, which will be followed by many more entries filled with knowledge and useful information about the things I learn daily.
Our first task is to read pages 544-552 and come up with 10 points you think is important.

• Electric current is when charge is carried through a conductor.
  
• Conventional current is when current flow moves from the positive terminal to the negative terminal of a power source.
  
• I is measured in amperes (A), Q is the charge measured in coulombs (C), and t is the time in seconds.
• Current, C/s, is the rate of charge flow and is given the symbol I. It is the complete amount of charge moving past a point in a conductor divided by the time it takes.
• Ammeters are devices used to measure current, which needs to be wired in order for the current to flow through it. It needs to be an excellent conductor so that so energy is lost when something else is added to the circuit.
  
• Direct current (DC) is the flow of current in a single direction from the power supply through the conductor to the load, which could be a light bulb, and back to the power supply.
  
• Alternating current (AC) is when the electrons periodically reverse the direction of their flow.
  

Here is a picture of a simple circuit. The path of a current is called a circuit and it is required for any electrical device to work properly.
TIP: In order to be successful in drawing circuits, you need to learn the symbols provided for different items. For more help, look at page 547 in your textbook.

• Electrical potential difference (v) is the electrical potential energy for each coulomb of charge in a circuit.
  
• Voltage is the potential difference of a charge. One volt is the electric potential difference between two points if one joule (J) is needed to move one coulomb (C) of charge of two points.
  
• E=VIt is the energy transferred by charge flow, where E is the energy measured in joules, V is the potential difference in volts, I is the current which is measured in amperes, and t is the time in seconds.
  
• A Voltmeter can be used to measure the potential difference between two points. It must be connected in parallel with one of the loads in the circuit so that the potential before and after can be determined.
  

Here is the list of symbols you need to know for drawing circuits.
Enjoy !

-Peggy.