Unit4_KoscielnyD

= Lessons 39 & 40 = toc

Ions
anion- extra eletron(s) cation- atom missing, (one or more electron or proton) -protons are much larger than electrons - posotive charges create "low electric pressure"because it depletes electrons - an electron causes high pressure

Introduction to Charge
-all electrons are identical - in Coulombs (C), and micro and nano - symbols is Q or q -conductors allow charge to flow easily - insulators make charge travel slowly <--perfect insulator---rubber--wood--salt--water--granite--aluminum--chlorinated water- iron--silver--copper--gold---perfect conductor--> - the perfect insulator does not allow charge to flow easily - the perfect conductor allows charge to move easily -opposite charges attract and similar charges repel d2) ||  || Practice problem:
 * Electric Force ||  ||
 * Fe is proportional to 1/(
 * Fe is proportional to q ||  ||
 * repulsive or attractive ||  ||
 * Fe = ke |q1q2|/r2 ||  ||
 * ke, aka kc, is a constant ||  ||

Charge Transfer
neutral = uncharged
 * chart from worksheet
 * practice problems from worksheet

Electric Field
- the electric field is the region of space in which annother charged object experiences an electric force - E is the electric field strenght E = F/q = ke q/r2 - unit is N/C - the direction of other object is always in line with the source- + directly away from +, - directly towards +

Four characteristics:
 * 1) lines point away from + and towards -
 * 2) the more lines, the stronger the field
 * 3) lines can be drawn on any charged object
 * 4) field lines never intersect each other

- charge concentrates at pointy parts of your body (fingers, hair)

Sticky Tape Lab
HANDED IN

=  Homework  = **Reading Summary:**

Basic Terminology and Concepts __ [|The Structure of Matter] __ Everything has electrical properties and is made up of **molecules/compounds** made up **elements/atoms** made up of a negative **electrons** that can hop around and a non-moving **nucleus** made up of positive **protons** and neutral **neutrons**.

__ [|Neutral vs. Charged Objects] __ When #protons= #neutrons, it is an **electrically neutral atom**, but when they are unequal it is a **positively/negatively charged ion**.

__ [|Charge Interactions] __


 * Electrical Force** is **attractive** between opposites and **repulsive** between things with the same charge.

__ [|Conductors and Insulators] __


 * Conductors** transfer energy easily and **Insulators** do not transfer energy easily.

__ [|Polarization] __ When electrons are **induced**, the object becomes **polarized**, but this does not mean that the object is charged; a **polar bond** is when the electrons from two atoms' **electron clouds** share electrons. ---

Methods of Charging __ [|Charging by Friction] __ You can form a **tribolectric series** by putting materials in order based on their **electron affinity**; though electrons can be transferred (as through friction), the net charge is always conserved.

__ [|Charging by Induction] __
 * Charging by Induction** is when you polarize a system and take it apart so the parts have different charges.

__ [|Charging by Conduction] __
 * Charging by contact**/ **Charging by conduction** is when charge is transferred through objects in contact, as opposed to **charging by lightning** where electrons flash through air to get to a nearby positive object.

__ [|Grounding - the Removal of a Charge] __
 * Grounding** is the removing of uneven charge by exchanging electrons through conduction.

--=--

Electric Force __ [|Charge Interactions Revisited] __ The force of electricity acts on charged objects just as previously studied forces.

__ [|Coulomb's Law] __ The force of electricity is dependent of the charge of each object and the distance between them.

__ [|Inverse Square Law] __ The relationship between force and distance is inverse square.

__ [|Newton's Laws and the Electrical Force] __ Electric force acts like other forces.

---

Electric Fields __ [|Action-at-a-Distance] __
 * Action-at-a-distance** is possible because of **field force** of **electric fields**.

__ [|Electric Field Intensity] __
 * Source Charge** is the charge of the thing being tested while **test charge** is the charge used to measure the source.

, __ [|Electric Field Lines] __
 * Electric Field Lines** are drawn in the direction of the negative and the farther apart the lines the lesser the charge, these lines can bend when they near lines from other sources but never cross.

__ [|Electric Fields and Conductors] __
 * Electrostatic** **Equilibrium** is when charge is no longer moving so the net electric force is 0, **Faraday's cage** shields objects inside it from electricity- **shielding** is often used for electronics.

__ [|Lightning] __ The air acts as a conductive **plasma** for the (originally static) electricity; a **step leader** of electrons zigzgging towards the ground and meets rising positive charge called the streamer, then the lighting is formed- **lighting rods** ground the charge preventing fires and property damage.

**Jokes:** Two atoms were walking across a road when one of them said, "I think I lost an electron!" "Really!" the other replied, "Are you sure?" "Yes, I 'm absolutely positive."

--- Warnings manufacturers ought to put on all products:

NOTE: Despite its appearance, this product is more than 99.99% empty space.

HANDLE WITH CARE: This product contains countless, minute, electrically charged particles moving at extremely high speeds.

QUALITY STANDARD: The electrons, protons and neutrons are guaranteed to be of same quality as those used in other products of the Manufacturer.

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 * Both jokes from:**

= Lessons 41 & 42 =

Electric Potential Energy
>
 * You need to do work to draw two repelled objects close to each other but when you do you get electric potential energy due to the position in the electric field- like GPE.
 * Work done= change in EPE
 * EPE is the total money you spend, but the price per item is **__Electric Potential (V)__**
 * V=EPE/q= -w/q
 * measured in: Volt= J/C
 * Electric Potential= Eclectic Potential Difference= Electric Pressure= Voltage
 * DIFFERENT FROM ELECTRIC POTENTIAL ENERGY
 * all energy is __**SCALAR**__
 * V= E*d
 * not all voltage is equal in energy- energy is in Joules not volts and volts are J/C
 * foe current to flow it has to go from high potential to low potential
 * batteries are sources of potential engergy- high pressure at one end and low at the other- it acts as a pump, pushing charge out of high and into low

Basic Electric Circuit Activities
HANDED IN

=  Homework  = **Reading Summary:**

__ [|Electric Field and the Movement of Charge] __
Work is required only to increase **Electric Potential Energy** by moving subatomic particles in a direction they would not go on their own.

__ [|Electric Potential] __

 * Electric Potential** is based on an object's charge and distance from a source.

__ [|Electric Potential Difference] __

 * Electric potential difference** is the difference in EP between the initial and final points; similarly, **voltage drop** is how much voltage is lost as it goes through the circuit from the **internal** (battery pack) and **external** (wires and light bulb)

-=-=-=-

__ [|What is an Electric Circuit?] __
When an **electric circuit** is completed, there is a **current**.

__ [|Requirements of a Circuit] __
There must be an unbroken conductive path leading from the positive to the negative terminal of the battery to form a circuit- for a light bulb to light, the filament has to be included in the circuit so the tip and side must be the entry and exit points.

__ [|Electric Current] __
**1 ampere = 1 coulomb / 1 second**
 * Current** is the rate at which charge passes a certain point, the direction is from + to -; **drift speed** is how quickly the charge carrier moves on average.

__ [|Power: Putting Charges to Work] __
if you make a circuit without a **load** it drains quickly; power is how much energy is supplied by a battery or used by a load. **1 watt = 1 joule / second**

__ [|Common Misconceptions Regarding Electric Circuits] __
Charge in circuits comes from wires, batteries just "push" the charge, which slow-moving but looks instantaneous because it all moves at once, energy is converted in appliances.

**Jokes:** Q: Why didnt the malfunctioning circuit have any friends? A: His short temper.

= Lessons 43 & 44 =

Circuits
- circuit= closed loop of conducting materials that form a conducting path - current= the measure of charge flow in a circuit SYMBOL: I UNIT: Amperes (A) EQUATION: Q/t IS A FLOW RATE - flow rate= #/time - speed= d/t - Change in pressure in a straw is voltage - resistance= R= the ability of a material to oppose/hinder current UNIT: OHM (omega) - everything between the perfect insulator and the perfect conductor is a resister - battery is source of pushing- material is source of charge



Ohm's Law Lab
__Hypothesis:__ V=IR, so the current-voltage relationship will be linear with resistance as the slope. A light bulb should act like a resistor. __Data:__ __Error Calculation:__ I1618.6-4700I/4700= 0.656 65.6% error
 * Theo-Exp|/Theo= % Error

__Graphs:__

__Analysis:__ The linear quality of the resistor graph proves Ohm's law and shows that the resistance is constant. The curved line in the bulb graph shows that the light bulbs resistance was not linear as I hypothesized, but changed: this is probably because the light bulb became hotter and the heat changed the resistance. The great amount of error was due to the fact that the analogue devices we used to measure the values were not particularly accurate or precise, and there was room for human error in the reading of them.

__Questions:__

=  Homework  = **Reading Summary:**

__ [|Journey of a Typical Electron] __

 * Voltage drop** is due to load and lost charge due to slight charge loss in the wire.

__ [|Resistance] __

 * Resistance** is how much flow of charge is hindered.

__ [|Ohm's Law] __
**V = I • R**
 * Ohm's law** states that EP difference between two points on a circuit ([[image:http://www.physicsclassroom.com/Class/circuits/rdbddelta.gif width="8" height="8" align="bottom"]] **V** ) equals the product of the current between those two points ( **I** ) and the total resistance of the load between the points ( **R** ).

__ [|Power Revisited] __
Electric power is related to Ohm's law and uses three equations derived from one. V = (I • R) I = V / R

__ [|Circuit Symbols and Circuit Diagrams] __
Circuits can be described with words, drawings, and diagrams. > Description with Words: Three D-cells are placed in a battery pack to power a circuit containing three light bulbs.



__ [|Two Types of Connections] __
Connections can be **parallel** or **in** **series**.



__ [|Series Circuits] __
In a series circuit, there is only one pathway for charge to follow and the current at any location is the same as at any other location.

**Vbattery =** **V1 +**  **V2 +**  **V3 + ...**
 * Ibattery = I1 = I2 = I3 = [[image:http://www.physicsclassroom.com/Class/circuits/rdbddelta.gif width="8" height="8" align="bottom"]]Vbattery / Req**
 * Req = R1 + R2 + R3 + ...**

__ [|Parallel Circuits] __
In P-circuits each device has its own separate branch.

__ [|Combination Circuits] __
C-circuits have both parts. =

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