PS+6+-+3rd+Period+Brown

PS 6- Interactions of Matter and Energy- Energy Energy Intro to Energy
 * Definitions **

-Electrical Energy- movement of electric charges -Chemical Energy- energy stored in the bonds of atoms and molecules -Thermal Energy- movement/vibration of atoms and molecules in substance

-Kinetic Energy- energy in the form of motion (kinetic= ½ m*v ^2)

-Potential Energy- stored energy due to position

-Gravitational Potential Energy- energy stored by objects that are above Earth’s surface

Conservation of Energy

-Electrical Energy- movement of electric charges -Energy Transformation- the conversion of one type of energy to another type -Thermal Energy- movement/vibration of atoms and molecules in substance on an object

-Electric Charges- they make the charge of an object; either positive or negative

-Conservation of Charge- charge is never created nor destroyed; only moved from one object to another

-Opposites Attract- negative attracts positive; negative repels negative; positive repels positive -Conductors- electrons can move easily through them

-Insulators- materials that don’t allow electrons to move easily through them

-Metal Conductors- atoms in metals have electrons that easily move through materials

-Induction- objects can be charged by bringing a charged object near a neutral one

-Friction- charging by rubbing two objects together; electrons leave one and stick to another

-Conduction- electrons being transferred from one object to another by Touching

Electricity -Voltage- the difference in electrical potential between two places where electrons are flowing

-Volts- units of voltage

-Current- the flow of electric charges

-Amps- units of current

-Battery- electron pump

-Resistance- opposition to the flow of electrons

-Conductor- less resistance than insulators

-Insulators- more resistance that conductors

-3 Ways to Increase Resistance in Wire- longer wires; thinner wires; higher temperature

-Ohm’s Law- current= voltage difference/resistance

-Series Circuit- one path; any break, then all go out; current is the same throughout the circurit

-Parallel Circuit- multiple paths; if any break in one branch, then others will still be on; voltage is same in each branch, but current and resistacne may be different

-Fuses- electrical safety device; one time use

-Light Bulbs- have a tiny filament that resist the flow of electrons; filament gets hot and glows to produce light

-Batteries- electron pumps

-Chemical Cells- converts chemical energy into electrical energy



Electricity and Magnetism

- Magnetism- the properties of attraction possessed by magnets; the molecular properties common to magnets -Magnetic poles- positive pole and negative pole

-Magnetic Field- the region of space surrounding a magnet

-Electromagnet- a temporary magnet made by placing a piece of iron inside a current- carrying coil of wire

-Speaker- electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance

-Motor- a device that changes electrical energy into mechanical energy

-Commutator- reverses the poles of the electromagnet

-Electromagnetic Induction- the production of an electric current by moving a loop of wire through a magnetic field or moving a magnet through a wire loop

-Electric Generator- a device that produces electric current by rotating a coil or wire in a magnetic field

-Direct Current- current that only flows one direction through a wire

- Alternating Current- reverses the direction of current flow in a regular way

__ Questions  __ ** (D. 9 volts)**
 * 1) The law of conservation of energy implies which one of the following statements?
 * 2) Light energy is always decreasing.
 * 3) The kinetic energy of a moving object is always equal to its potential energy.
 * 4) The amount of energy in a closed system remains constant.
 * 5) Thermal energy is always increasing.
 * (C. The amount of energy in a closed system remains constant.) **
 * 1) Which of the following is a device that transforms mechanical energy into electrical energy?
 * 2) Blender
 * 3) Car engine
 * 4) Hydroelectric dam
 * 5) Flashlight
 * (C. Hydroelectric Dam) **
 * 1) Which is an example of chemical energy?
 * 2) Horse pulling a cart
 * 3) Thermos of hot coffee
 * 4) Food
 * 5) Marching band in a parade
 * (C. Food) **
 * 1)  Which of the following is a conversion from chemical energy to thermal energy?
 * 2) Coal is burned to boil water.
 * 3) Food is digested and used to regulate body temperature.
 * 4) Charcoal is burned in a barbeque pit.
 * 5) All of the above.
 * (D. All of the above) **
 * 1) Which of the following is the best example of increasing an object's potential energy?
 * 2) Rolling a bowling ball
 * 3) Turning on a light bulb
 * 4) Stretching a rubber band
 * 5) Dropping a pencil
 * (C. stretching a rubber band) **
 * 1) An object that has kinetic energy must be...
 * 2) Lifted above earth's surface.
 * 3) In motion
 * 4) At rest.
 * 5) None of the above.
 * (B. in motion) **
 * 1) Thermal energy is...
 * 2) Kinetic.
 * 3) Potential.
 * 4) Both kinetic and potential.
 * 5) Neither kinetic nor potential.
 * (A. kinetic) **
 * 1) Sound energy is...
 * 2) The energy of a compound that changes as its atoms are rearranged to form new compounds.
 * 3) The total energy of the particles that make up an object. (your answer)
 * 4) The energy caused by an object's vibrations. (correct answer)
 * 5) The energy of motion.
 * (C. the energy caused by an object’s vibrations) **
 * 1) What device converts chemical energy to mechanical energy?
 * 2) human
 * 3) car
 * 4) jet ski
 * 5) All of the above
 * (D. All of the above) **
 * 1) Which of the following is not a voltage source?
 * 2) Battery
 * 3) Gasoline
 * 4) Solar Cell
 * 5) Generator
 * (B. Gasoline) **
 * 1) If a simple circuit has one resistor of 3 ohms and a current of 3 amps, how many volts is the power source?
 * 2) 6 volts
 * 3) 18 volts
 * 4) 3 volts
 * 5) 9 volts
 * 1) If a second resistor of 3 ohms is added in series to the circuit from question 11, how much must we increase the voltage to get the same current through the circuit?
 * 2) We should increase the voltage by 6 volts.
 * 3) We should increase the voltage by 2 volts.
 * 4) We should increase the voltage by 9 volts.
 * 5) We should increase the voltage by 19 volts.
 * (C. We should increase the voltage by 9 volts.) **
 * 1) A simple circuit has two resistors in parallel. Each resistor has a resistance on 6 ohms. The current through the whole circuit is 2 amps. What is the voltage of the voltage source?
 * 2) 3 volts
 * 3) 9 volts
 * 4) 4 volts
 * 5) 6 volts
 * (D. 6 volts) **
 * 1) In the same circuit as in question 13, the voltage source is replaced with one of 12 volts. What is the current through the whole circuit?
 * 2) 6 amps
 * 3) 4 amps
 * 4) 3 amps
 * 5) 9 amps
 * (B. 4 amps) **
 * 1) If you apply a constant force of 1 N on a book to pick it up off the floor and set it on a desk 1 m high, how much work did you do on the book?
 * 2) 0.5 J
 * 3) 1 J
 * 4) 5 J
 * 5) 10 J
 * (B. 1 J) **

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