THIS+IS+Kane's+page

KANES page full of PHYSICS knowledge

Kane - get this page happening stat! We have a code khaki (Which means no homework, classwork or even any irrelevant pictures) - it is urgent. You need to call the crash cart and save the life of this page before it is too late! PS If you go to Student Public - Curriculum - Year 11 - Physics and go into Mr Coloumb Takes Charge you can catch up on what you missed today. Summarise Chapters 1&2 on your wiki page. 1219804142

__Homework:__
A stun gun works by mixing up the electric signals in your body. This is so because when your brain sends signals to your arms it sends electrical signals that travel through you nerves. When a taser hits you it sends like 50 volts through your body scrambling the signals leaving you pretty much unable to move.

The best way to avoid being struck by lightning is to get indoors when it looks like there might be lightning about if you cant then you should try to stay low and try to stay dry as most of the time lightning strikes the highest object and usaully something that can conduct it.

Lightning: When moisture in clouds collide it causes electons to be knocked off creating charge seperation. When there is a charge separation in a cloud, there is also an **electric field** that is associated with the separation. Like the cloud, this field is negative in the lower region and positive in the upper region. The strength or intensity of the electric field is directly related to the amount of charge buildup in the cloud. As the collisions and freezing continue to occur and the charges at the top and bottom of the cloud increase, the electric field becomes more and more intense -- so intense, in fact, that the electrons at the earth's surface are repelled deeper into the earth by the strong negative charge at the lower portion of the cloud. This **repulsion of electrons** causes the earth's surface to acquire a strong positive charge. All that is needed now is a **conductive path** for the negative cloud bottom to contact the positive earth surface. The strong electric field, being somewhat self-sufficient, creates this path. information from 'how stuff works'        =VIt/t= VI  
 * The magnitude charge is called the elementary charge. Symbol e. Another measurement is the coulomb symbol c.
 * One coulomb of charge is same as 6.242x10^18 or one elementary charge is 1.602x10^ -19 coulomb.
 * Electrons are the only thing that move to change charge
 * charge of moved elctrons both equal to zero, no atoms creat or destroyed.
 * objects of different charge attract
 * insulators cause electrons to build up while conductors cause electrons to be evenly placed throughout the conductor.
 * insulators cause more static electricity
 * [[image:static_equ.PNG]]
 * F: the force between the charges, measured in Newtons (N)
 * k: the proportionality constant, which is equal to 9.0x10^9 Nm^2C^-2
 * q's represents two charges - measured in coulombs (C)
 * r: is the distance between the two charges, measured in meters (m)
 * An electric field (E) is defined as E=F/Q
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E is the strength of the field (N/C)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">F is the force (N)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">q is the amount of charge (C)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">A battery has moving charged particles
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">The term current means the conventional current meaning the path that the prontons appear to be moving which is opposite the electron current.
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">[[image:amps_equ.PNG]]
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">I is the current in amperes (A)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">q is the amount of charge, Coulombs (C)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">t is the amount of time seconds (S)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">DC - direct current because the current is always moving in the same direction
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">AC - alternating current meaning the current is moving backwards and forewards
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">The amount of energy given to each coulomb of charge in the battery is called the electromotive force (EMF) measured in Volts
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">Voltage is another name for EMF and also Potential difference (PD) is another name for it.
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">Equation V=JC is the amount of energy given to a coulomb of charge
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">wires in a circut are heat resistant
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">resistance R=V/I
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">R is the resistance in ohms
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">V is voltage in volts (V)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">I is the current in amperes (A)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">two types of conductors non-ohmic and ohmic
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">ohmic follows the law that V-I the voltage going through a conductor is directly proportional to the current going through it
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">resistance is the same all the time
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">non-ohmic conductors have the resistance change under different conditions, eg. light intensity, sound intensity or temperature
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">Ohmic resistors are ohmic conductors
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">non-ohmic devices include light bulbs, diodes and thermistors
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">resistance in wire depends on the lenght, the thickness and the cross-section area, and the material
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">resistance by material is called resistivity in (p) pronounced rho
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">R=pL/A
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">R resistance
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">p the resistivity of material
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">L lenght of wire (m)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">A the cross section of area of wire (m squared)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E=qV
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E amount of electric energy (J)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">q amount of charge (C)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">V potential difference(V)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">q=It
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">therefore = E=VIt
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">P = E/t
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E = VIt
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">P
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">P amount of power in watts (W)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E amount of energy in (J)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">t is amount of time (S)
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">E = Pt
 * <span style="FONT-FAMILY: Arial, Helvetica, sans-serif">one kilowatt is 1000 watts by 3600 seconds. a kilowatt an hour is same as 3600000 joules

> > <span style="COLOR: #8507bb; FONT-FAMILY: Georgia, serif">It works by the principle of electro magnetic induction founded by Michael Faraday. Which <span style="COLOR: #9015cb; FONT-FAMILY: Georgia, serif">is t <span style="COLOR: #9015cb; FONT-FAMILY: Georgia, serif">he use of magnetism to produce electricity. > A changing magnetic field can induce an electrical current in an adjacent wire. For this to happen, ie energy transfer to takeplace, both the wires should have same resonant frequency > Wireless sending of energy is usually not very efficient because most of the energy which is sent misses the receiver, or is lost as heat. Sending energy through wires, on the other hand, loses much less power, because wires confine and guide the energy to where it is needed. Generally, wireless energy transfer works best at short range; although long distances are possible if the transmitters and receivers are physically large, or the energy can be formed into a tight beam, such as with lasers or large microwave dishes. <span style="FONT-FAMILY: Arial, Helvetica, sans-serif"> <span style="FONT-FAMILY: Arial, Helvetica, sans-serif"> <span style="FONT-FAMILY: Arial, Helvetica, sans-serif"> <span style="FONT-FAMILY: Arial, Helvetica, sans-serif"> Kane - well done - this is looking fantastic! Your summary is detailed, excellent job o nth homework (Love the videos). Great effort, I am so proud!1220489317
 * **<span style="COLOR: #1667d4; FONT-FAMILY: Georgia, serif">How does wireless power work? ** [[image:http://static.howstuffworks.com/gif/wireless-power-5.jpg width="330" height="236" caption="The Stationary High Altitude Relay Platform (SHARP) plane could run off wireless power beamed from Earth."]]
 * Can we create power here to use in foreign countries?
 * How much electricity would it take to kill a large camel?[[image:http://c2.wikicdn.com/s/rte/images/image.gif width="22" height="23" caption="Insert Images and Files"]]

Looks strangley familiar.... -eslin The only things he's missin is the chicken horse 1221008073 This is colorfull and well organised. --1221008285 Yay! It's colour-ma-ful! 10.5 E-10 Stars! 1221008338

HOMEWORK
 * Why is a sweaty body electrically more dangerous than a dry body?
 * Why do some trees explode when struck by lightning?
 * What is the difference between AC and DC current?
 * Power lines are operated at high voltages and low currents. Why?
 * They are trying to develop an electronic means of contraception. Explain how this could work.

DC is direct current and AC is Alternating Current. An alternating current (AC) is an electric current whose direction reverses cyclically, as opposed to direct current, whose direction remains constant. The usual waveform of an AC power circuit is a sine wave, as this results in the most efficient transmission of energy. However in certain applications different waveforms are used, such as triangular or square waves .**
 * A sweaty body is wet and electric conducts better in water so a wet body conducts more than a dry body.
 * Some trees can explode when struck by lightning. The strong electric current is carried mostly by the water-conducting sapwood below the bark, heating it up and boiling the water. The pressure of the steam can make the trunk burst. In Australia, the native eucalyptus trees are also known to explode during bush fires due to the high flammability of vapourised eucalyptus oil produced by the tree naturally. **