Coulomb's Law
F=k(q1q2/d2)
Why does your hair stand up when you take off a hat?
Hat and hair charged by friction. The like charges repel each other and make the hair on your head stand up
Induction? Other ways to charge things?
Induction steals the electrons from an object and makes the object positively charged. Friction and contact are the other ways of charging.
The Difference Between AC and DC
AC stands for 'alternating current'. This means that the current will alternate directions.
DC stands for 'direct current'. This means that the current will keep the same direction throughout.
What is Voltage?
Potential Difference.
Change in PE/ charge
V=(change in PE)/q
Units
Volts (V) = Joules/Coulomb
Energy given to each Coulomb of charged, measured across two points.
What is current?
current is the flow of charge
Units
Amps (A)= Coulombs/second
Current goes through the circuit
What is Resistance?
Resistance is the resistance to the flow of charge.
Unit
Ohms (omega symbol)
AC stands for 'alternating current'. This means that the current will alternate directions.
DC stands for 'direct current'. This means that the current will keep the same direction throughout.
What is Voltage?
Potential Difference.
Change in PE/ charge
V=(change in PE)/q
Units
Volts (V) = Joules/Coulomb
Energy given to each Coulomb of charged, measured across two points.
What is current?
current is the flow of charge
Units
Amps (A)= Coulombs/second
Current goes through the circuit
What is Resistance?
Resistance is the resistance to the flow of charge.
Unit
Ohms (omega symbol)
Things to Remember:
The electrons that flow are already in the circuit. The actual speed of electrons is extremely slow (think snail's pace).
The Energy/Electric Field travels at neat the speed of light (NOT the electrons themselves... REMEMBER!!! Snail's pace!!)
When something is charged, it means that there is a 'imbalance of protons vs. electrons. To charge an object, charges must be transferred.'
There are 3 methods of charging:
1.) Contact
2.) Friction
3.) Induction
When something is Polarized it means that the the charges within an object have rearranged themselves and that the Net charge still equals zero. This does not mean that the object is now charged.
Electronic Shielding
(Electric field/ Electric force inside a conductor=0)
Ohm's Law is V=IR
Coulomb's Law
F=k(q1q2/d*2)
The changes in distance affect changes in force shown by:
2d=1/4F and 1/2d=4F
Power=VI
Different filaments have different resistances. The resistance of something can increase in three ways:
1.) longer
2.) thinner
3.) both longer and thinner
What was difficult for me this unit was my organization, or more realistically the lack-there-of. my non-existent organization this unit is making my efforts in studying harder and harder. Next unit, I really need to make a designated binder to keep my quizzes, notes, and handouts in. My poor organization skills are going to kill my grade.