Unit++4

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Hw: static electricity
Atoms are the smallest particle that contains an elemental characteristic. they are composed of electrons, protons and neutrons. protons are located in the nucleus and the electrons are in the outer electron shell. A charged particle has either a positive or negative charge by having an uneven amount of electrons. An object is neutral if it has an equal number of protons and electrons. The charge of an object is represented in Coulombs, a scientific unit. Electric charge is the measure of the effect of a different number of electrons and protons. If an object has a charge than it is no longer neutral and can attract or repel other charged objects. Electric force is the force that charged objects place on each other when they attract or repel. This force is responsible for unique properties of charged objects. It depends on coulombs constant. Directly proportional to the charges ad inversely proportional to the square distance Electric field is the area around a charged object where the electric force has an effect. The further the object is the weaker the force and the field. The region of space where a charged particle will feel an influence of another charged particle. Directly proportional to the charge. 4 ways to charge an object, induction, conduction, friction, polarization Polarization is separating the charge on a neutral object so that opposite ends have opposite charges. Induction is Charging without touching the charged objects together. The electric field of the charged objects works to move charges without touch. Charging can also be done by friction where one objects strips electrons from another object. Charging by conduction is charging through touch where the positive or negative object when touched to a neutral object will either attract or repel electrons and change the charge of the neutral object. Charges can be removed By grounding an object. In this process a charged object is connected to a much larger object that will neutralize the charge and take in the extra electrons or give extra electrons with little effect on the larger object. Electric force: Electric force is force that is due to polarized or charged objects attracting or repelling each other. If the force difference between opposite forces are 0, the situation is at equilibrium. The strength of electric force can be described with vector quantity. Coulomb's Law is the effects of three variable on electric force: F = (k)*(Q1)*(Q2) / (d ^2). Q1 represents charge of object 1, Q2 represents charge of object 2, d represents distance between the objects and k represents coulomb's law constant: 9.0 E 9 (Nm^2) / C^2. Coulomb's law is similar to the gravitational force law. The charge of object is directly related with electric force. The distance between objects and electric force has inverse square relationship. Electric field: Electric force that is causes action in a distance. Charges can attract and repel even they charged objects are far away from each. Changed object creates the electric field that the region surround it. One most common example is Van de Graaff generator. Due to great charge of van de graaff generator, bigger electric field will formed. Electric field strength is vector quantity. Electric field strength = Force / Charge. Electric field strength = k * Q * q / d^2 / q. HW DELETED BY WIKI....... []

Hw: Electric current:
An electric force is an action at a distance force. They create a field of force. The space surrounding a charged object is known as its electric field. Electric fields act like gravitational fields. To move a charge in an electric field against its natural direction of motion would require work. This work then is converted to a potential energy.

The closer to a charged object the stronger the electrical force. Electric potential energy is the energy stored in an object based on a charged object due to its electric field. The larger the charge the more work is necessary. The amount of force involved in doing the work is dependent upon the amount of charge being moved (according to Coulomb's law of electric force). The greater the charge on the test charge, the greater the repulsive force and the more work that would have to be done on it to move it the same distance. Work=delta PE __Electric potential = electric potential difference, Electric pressure, voltage__ Amount of energy per charge V – Electric potential V= delta PE/q or –W/q Volt = J/C the electric potential difference is the difference in electric potential (V) between the final and the initial location when work is done upon a charge to change its potential energy. an internal circuit is the part of the circuit where energy is being supplied to the charge, an external charge is the part of the circuit where charge is moving outside the cells through the wires on its path from the high potential terminal to the low potential terminal. Current: Current is the flow of charge in a circuit. In a circuit electrons flow from regions of high pressure to areas of low pressure or the positive areas. If there is an electric potential different than it can push charge from one place to another. Charge will naturally move towards a region of less potential. For a circuit to work it must be continuous and unbroken. The bulb connected to it needs to have flow in the thread and the tip for the light to show. Circuit- a CCP that includes a source of potential (power supply) 4. Both ends of a battery must be included in a circuit. Current flows from areas of positive towards the negative and back again. This is strange because it is the electrons that are moving. Drift speed is the average distance traveled by a charge carrier per unit of time. Although the movement of the particles seem to be slow the entire system is acted upon at one time, immediately. Power is the rate at which electrical energy is supplied to a circuit or consumed by a load. Load is the electrical energy supplied to the charge by the battery that is transformed into other forms in the electrical device.
 * Electric potential Energy**: (total amount of money spent)
 * Electric potential**: (price per unit of clothing)
 * 1) In order for a bulb to light there must be no breaks in the circuit. Closed loop. Both bulbs light at the same time.
 * 2) Conductive materials must be used to form a closed loop.
 * 3) Continuous conducting path (CCP) through a light bulb must include the threaded side and tip. CCP is a series of connected materials that form a close loop.

=Lab: Pressure difference and flow rate= Objective: Determine the relationship between pressure difference and flow rate for a bulb and a resistor. Hypothesis: the relationship for both the bulb and the resistor will be direct and linear. Data:

Analysis: In this lab we tried to prove that the relationship between pressure difference and flow rate was a direct relationship. The graph proves that this hypothesis is correct with a direct linear graph for each resistor. The equation of the line shows that the slope should be equal to the resistivity of the resistor however the experiment was very inaccurate and gave me a very high percent error for each test. This was due partly to human error in reading meters and in part to the meters themselves being inaccurate and old. The Graph of the bulb showed that i was wrong in my hypothesis and the relationship is really a power fit. This is because the bulb is a very non consistent material and changes with temperature and use. Questions:

- Resistance blocks the flow of electricity. The unit is Ohms. - If the pressure difference decreases, the flow rate must also decrease to maintain the same resistance. Ohms= pressure difference/flow rate. - Both graphs should have a flat line because the resistance does not change when the other parts change. - 220V/10A=22ohms. - R= v/I 6=9/I = 3/2A. - (1,5) (2,10) (y1-y2)/(x1-x2) The slope is five.
 * 1) In terms of experimental data how is the resistance defined and what are its units?
 * 1) Imagine that you are a third resister that has a musch smaller resistace than the ones used ina lab activity.
 * 2) The smaller resistance will make a shallower resistance on a graph. Thus, the line for the third resister should be less steep.
 * 3) How would the flow rate through the resister change as the pressure difference decreases?
 * 1) Assume that resister A has ten times the resistance of resister B. What would the graph of resistance vs. current look like for these two resisters?
 * 1) While cooking dinner school’s dining hall uses a 220V line and draws 10A of current when heated to its maximum temperature. What is the resistance of the oven when fully heated?
 * 1) A0V battery to a 6Ohms resister. What will the flow rate of the resister be?
 * 1) Ohmic
 * 2) What is the resistance of an object from which the

Hw: Resistance
The difference in potential causes electron flow. when electrons move through a wire they move in a zig zag motion and do not go straight. this is the reason that the flow is often slow. The collisions of charge carriers in an electric circuit with the conducting elements of that circuit result in a loss of energy.Flow rate is how many charges cross a point in an amount of time. As electrons flow through a wire energy is lost and the movement is slowed there fore causing the voltage to drop. Resistance (R) – The ability of a material to hinder the flow of charge. (Current). The total length of the wires will affect the amount of resistance. The longer the wire, the more resistance that there will be. The cross-sectional area of the wires will affect the amount of resistance. Wider wires have a greater cross-sectional area. Current can flow much easier through a wide wire. Resistivity is a property of matter that refers to its ability to conduct. Ohms law: V = I • R. The electric potential difference between two points on a circuit is equal to the current times the resistance. this equation can be rearranges to find any variable. The current in a circuit is directly proportional to the electric potential difference impressed across its ends and inversely proportional to the total resistance offered by the external circuit.Current: The measure of charge flow in a circuit. Symbol= I (i) Ampere=A. I=Q/t Q=# of charges Power is the rate at which you do work. Voltage(potential difference) = work/q. W=Vq Electrical power is current* potential difference in Watts P=w/t = Vq/t (q/t=current) = VI P=I^2*R or V^2/R Circuit connections: A circuit can involve simply a battery and light bulb. A single cell or other power source is represented by a long and a short parallel line. A collection of cells or battery is represented by a collection of long and short parallel lines. Multiple electrical devices can be connected to a circuit in parallel or in series. Current stays constant throughout a series circuit but voltage changes. For parallel circuits, as the number of resistors increases, the overall current also increases. This increase in current is consistent with a decrease in overall resistance. In a parallel set up a bulb can be removed and the circuit will still work but if a series setup the circuit will not work if even only bulb was taken out. Series circuit: The equivalent resistance is the amount of resistance that a single resistor would need in order to equal the overall affect of the collection of resistors that are present in the circuit. Current is everywhere in a circuit moving at the same speed. The voltage of a battery is the sum of the voltages of all of the wires in a circuit. Parallel Circuit: In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another. The rate at which charge flows into a ode is equal to the sum of the flow rates in the individual branches beyond the node.