AP Physics 2 Terms

Thermodynamics

the exchange and conversion of heat energy between bodies

Kinetic energy(thermal)

K=3/2 nKbT or 3/2 nRT

n= number of particles

kb= maxwell boltzmann constant

R= universal gas constant

T = temperature

Maxwell-Bolton graph

Shows the average speed of particles throughout

Right is larger than the left, but the more scooched up it is means the more common it is

Where does thermal energy flow to

From hot to cold

How do the collisions between two gases’ molecules work

Random

Kinetic theory of gases

Gases have identical molecules unique to their certain gas

Volume is negligible

Density is constant at all point

Gas molecules exert pressure on container walls

The pressure of an ideal gas is the same everywhere

Ideal gas law

PV= NRT/Nkbt

P= Pressure

V = volume

N= number of molecules

Kb= boltzmann’s constant

T= temperature

Isochoric

Constant volume

Isothermic

Constant temperature

Isobaric

Constant pressure

Adiabatic

no heat transferred

Heating

transfer of energy into a system

Cooling

transfer of energy out of a system

Thermal equilbrium

two objects in a system/ two systems having the same temperature

Convection

heating through fluids

radioaction

heating through radioactive waves

Conduction

heating through direct contact

Internal energy(U)

Total energy of the whole system; total of each particles energy that does not have potential energy

U= Number of particles * average kinetic energy(N* Kavg)

Work on a gas

Positive during compression, negative during expansion; check same direction

W=-P(change in)V

Work by a gas

OPPOSITE DIRECTION; negative during compression, positive during expansion

Heat(Q)

thermal energy transferred from one body to another

Q = mcT

First law of thermodynamics

The change to energy is the sum of energy transferred to or from the system by heating work done of the system

U= Q + W

Insulated container

Energy does not escape

Rate of energy transfer by conduction

Q/t=kAT/L

Entropy

the amount of disorder in a system; tendency of energy to spread and the unavailability of the system to do work; highest in thermal equilibrium
Constant but can increase in a closed system

Increases when molecules/thermal energy spread out more

Isolated system

Energy stays the same

Charge

scalar quantity measured in coulombs; conserved

Elementary charge

e= 1.60×10^-19 Coulombs

Value of coulomb

6.25×10^18 electrons/protons

Coulomb’s law 

Force between 2 objects with charge

The two forces are in opposite directions

Coulomb’s constant

k= 1/4pie= 9×10^9 N*m²/c²

Electric polarization

rearrangement of electrons by an external electric field, separated by positive and negative charges

Electric permittivity

is a measurement of the degree to which a material/medium is polarized in the presence of an electric field, determined by how easily electrons can change configurations

Free space

Electric permittivity

conductor

material that does not allow electrons to move freely(metals)

insulator

material that doesn’t allow electrons to move freely(rubber, plastic, wood)

induction

charging with polarization and grounding(not touching)

transfer of charge

through WHOLE electrons friction, conduction, induction

Test charge

point charge of small magnitude that doesn’t affect an electric field nearby

Electric field

the ratio between electric force and charge exerted on a test charge

Acts as a positive particle

Field and force in the same direction

Charged particle in an electric field

Moves in a parabolic path

Field at the center of a solid conductor in electrostatic equilibrium

0

Electric potential energy

when the same charged particles are closer to each other PE is higher

one particle can’t have this
when there are multiple charges do it for multiple configurations

Electrical potential

Helps find potential energy if charge was placed

q1 is inital charge q2 is new

Charge flows until potential is the same

Perpendicular to the electric field

Same potential = no field or force, equilibrium

Field diagram

Closer together means higher potential for positive

Capacitors

oppositely charged parallel plates

Particles have constant acceleration in this

Electric potential energy increases with distance

Capacitance

ability to store electric charge

Capitance PE