Foundations Flashcards
Bulk Matter
consists of large number of atoms molecules or ions,
Properties of bulk matter
the state of a sample of matter is defined by specifying the values of various properties. Among them are
mass
volume
amount of substance
Translation
the motion of a particle through space
Velocity
the rate of change of its position
v=dr/dt
Linear momentum
of a particle of mass m is related to its velocity,v , by
p=mv
angular momentum J
the rotational motion if a particle about a central point
J=Iω
ω-angular velocity
I-moment of inertia
Moment of Inertia
a measure of a bodys resistance to rotational acceleration
I=mr2
Newton’s 2nd law
the rate of change of momentum is equal to the force acting on the particle
dp/dt=F
Newtons
1 N = 1kgms-2
torque
a twisting force
T=dI/dt
Work
is done in order to achieve motion against an opposing force
- dw = -F*ds*
- F*ds=Fxdx + Fydy + Fz*
Energy
is the capacity to do work
Joule
1 J= 1N*m=1 kg m2 s-2
Power
the rate of supply of energy
1 W = 1 J s-1
kinetic energy
of a body is the energy the body possesses as a result of its motion
Ek = 1/2 mv2 = F2t2/2m
Potential Energy
of a body is the energy it possesses as a result of its position
total energy
of a particle is the sum of its kinetic and potential energies
Coulomb potential energy
the potential energy between two electrons charges
Thermodynamics
the systemic discussion of the transfer and transformation of energy in bulk matter
internal energy
total energy of a system
1st Law
states that the internal energy is constant in a system isolated from external influences
the internal energy of a sample of matter increases as its temperature is raised
ΔU = CΔT
Entropy
S, is a measure of the measure of the quality of the energy of a system
2nd Law of thermodynamics
states that any spontaneous (that is, natural) change in an isolated system is accompanied by an increase in the entropy of a system
the natural direction of change is accompanied by dispersal of energy from a localized region or its conversion to less organized from
Gibbs free energy
is a measure of the energy stored in a system that is free to do useful work
is at a minimum when temperature and pressure are constant
quantized
restricted to certain discrete values
theses permitted energies are called energy levels
allowed energies are widest apart - for particles of small mass confined to small regions of space
quantization is very unimportant for macroscopic bodies and very important for electrons in atoms and molecules
G = H - TS
Boltzmann distribution
Ni/Nj = e-(εi-εj)/kT
Average speed of molecules
Perfect gas
vmean =(8RT/πM)1/2
Wavelength
the distance between the neighbouring peaks of the wave
frequency
the number of time per secound at which its displacement ae a fixed point returns to its original value
electromagnetic field
an oscillating electric and magnetic disturbance that spreads as a harmonic wave through space
electric field
act on charged particle (whether stationary or moving)
magnetic field
acts only on moving charged particles
