Term
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Definition
| the measure of the average KE (translational only!) of the molecules of a substance |
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Term
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Definition
| energy transfer due to a difference in temperature |
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Term
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Definition
Tc=Tk-273.15
50=Tk-273.15
Tk=323.15K |
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Term
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Definition
500F=250C
250C=Tk-273.15
Tk=523.15K |
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Term
| Zeroth Law of Thermodynamics |
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Definition
| If 2 substances are in thermal equilibrium with a third, then the two substances are in thermal equilibrium |
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Term
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Definition
| Boyle's Law, Charles's law, and Gay-Lussac's Law |
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Term
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Definition
Pα1/V
As plunger moves down, pressure increases and volume decreases, temp is constant |
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Term
| Charles's law and example |
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Definition
VαT
heating up or cooling down a bottle of soda, pressure inside is constant |
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Term
| Gay-Lussac's Law and example |
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Definition
P α T
recording pressure and temperature readings in a container of water that is heated, iced, and at room temp |
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Term
| First Law of Thermodynamics |
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Definition
If a system undergoes change from an intial state to a final state, where Q is the energy transferred to the system by heat and W is the work doen on the system, the change in internal energy of the system is ΔU:
ΔU= Uf-Ui = Q+W
(energy input=energy output) |
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Term
| Second Law of Thermodynamics |
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Definition
No heat engine in a cycle can absorb energy from a reservoir and use it entirely for the performance of an equal amount of work
OR
When energy changes form, useful energy is ALWAYs degraded to non-useful energy |
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Term
| What do the laws of thermodynamics mean? |
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Definition
Ist--you can't get something for nothing
2nd--some energy must always be lost to the environment |
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Term
| Three properties of charges |
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Definition
1.Two types of charges (+ and -)
2.Charge is conserved (can't be created or destroyed)
3.Charge is quantized (has to be an integer) |
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Term
| How are neutral objects charged? |
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Definition
| Conduction(conductor(negatively charged) brought in contact with insulator(neutral charge)) or Induction (almost same as conduction, but no contact only repulsive forces) |
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Term
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Definition
| All materials where charge does not move freely in response to an electric force usually neutra, but become charged when rubbed by charged materials (conductors) |
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Term
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Definition
| materials in which electric charges move freely in response to an electric force |
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Term
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Definition
F=k(q1)(q2)/r^2
this establishes the fundamental law of electric force between two stationary charged particles--magnitude of electric force F between charges (q1 q2) separated by a distance r |
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Term
| Mass and Charge of an electron, proton, neutron |
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Definition
Electron:
mass=9.11x10^-31
charge=-1.6x10^-19
Proton:
mass=1.67x10^-27
charge=1.6x10^-19
Neutron:
mass=1.67x10^-27
charge=0 |
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Term
| Compare and contrast electric forces v. gravitational forces |
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Definition
Both are capable of acting through space, producing an effect even when there isn't any physical contact between objects involved.
However, electric forces are exerted on any other charged object within an electric field. The force is exerted by the field and gravitational force is the mutual force of attraction between two objects. |
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Term
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Definition
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Term
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Definition
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Term
| The electric field of a point charge is... |
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Definition
| away from positive, towards negative |
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Term
| What are electric field lines? |
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Definition
| NOT material objects, they are a pictorial representation of the electric field at various locations |
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Term
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Definition
ɸe=EAcosΘ
aka a net number of E field lines intersecting a surface |
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Term
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Definition
The only way to have a net number of E field lines intersecting a surface is to have a net charge inside the surface
GL=electric flux=q(enclosed)=E=kq/r^2 |
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Term
| Dangers of putting a closed can of beans on the fire |
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Definition
| If the bean can's volume is constant, then the can could explode. When you raise temperature, you also raise pressure which is stated by Gay-Lussac's Law P is proportional to T |
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Term
| Purpose of expansion joints in buildings |
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Definition
| They compensate for various changes in dimensions (V) with variations in temperature (T), also known as thermal expansion |
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Term
| Car mechanics put less air in tires during the summer than in the winter, why? |
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Definition
| Ideal gas law--all are proportional, so during summer and increase in temperature would mean an increase in pressure. To keep tires from blowing, the mechanic may decrease the volume by putting less air in, in order to allow for an increase in pressure. |
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Term
| Why is a car safe during electrical storms? |
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Definition
| Because the charges on the metal shell of the car will reside on the outer surface of the car, and the person inside the car touching the inner surfaces is safe. |
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Term
| Why does one's hair stand on end during an electrical storm? |
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Definition
| The net charge of the air is higher during the electrical storm, so the attractive forces between the arm hairs and the air are greater, arm hairs are charged by induction |
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Term
| Why does a charged comb pick up bits of paper? |
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Definition
| The comb is charged, and attracts bits of paper because of the displacement of charges in the paper (polarization) |
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Term
| Which way does air flow during the winter if the door is left open? |
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Definition
| Heat moves from a source of high temp to low temp..moves from inside to outside (heat engine) |
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Term
| What does temperature measure? |
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Definition
| the average kinetic energy of the molecules of a substance |
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Term
| Compare the electric forces and accelerations for the charges of a proton and electron places in identical electric fields |
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Definition
| the electric force on the proton is equal in magnitude to the force on the electron, but in opposite direction. The magnitude of the acceleration of the electron is greater than that of the proton. |
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Term
| 3 ways in which heat is transferred |
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Definition
| conduction, convection, and radiation |
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Term
| How doea a refrigerator work? |
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Definition
| Works by a heat pump operating in cooling mode, energy is extracted from the interior of the refrigerator and delivered to the warmer air in the kitchen as energy |
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Term
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Definition
| mechanism that takes in energy by heat and partially converts it to other forms (ME) |
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Term
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Definition
Basis for the Kelvin scale, equivalent to -273.15 celsius, gives a representation for lower bounds for physical processes
lowest possible temp where a substance transmits no thermal energy |
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Term
| 1st law of thermodynamics, in relation to humans |
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Definition
| humans do work (run, lift, walk, etc),and the internal energy of the body decreases, we replenish this by chemical potential energy stored in foods |
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Term
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Definition
| takes molecules and the relationships between pressure, temperature, and volume of gases and says that energy is conserved in all collisions of particles (conservation of matter) |
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