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Thermodynamics - Coggle Diagram
Thermodynamics
Laws
0.
Thermal equilibrium
2 substances mixed
heat gain/loss =
result
same temp
particles
still collide
heat
amount balanced
1.
Energy conservation
ΔInternal energy = ΔW+ΔQ
2.
Entropy
System disorder
More disorder ↑ entropy
ALWAYS ↑ overall
3.
Absolute zero
Impossible to reach
w/ finite steps
Specific heat capacity
Heat capacity
ratio
required heat (Q)
for ΔT
physical property
structure
Energy required
↑T
1kg by 1°C
w/out phase change
Same energy input
1/2 mass ↑Tx2
c
SHC
substance heated
ΔQ
quantity
energy supplied
m
mass
body heated
ΔT
Δ temperature
Units
joules/kg/kelvin
Energy transfer models
Heat energy
moves
region high T
to low
Convection
Also 'thermals'
cause
T difference
between air masses
Heat energy
transfer
via
bulk particle movement
particle flow
away
warmer to cooler
current produced
Fluids ONLY
Heated expand
less dense
more buoyant
float
cold contract
more dense
less buoyant
sink
occur
warm & cold
fluid masses intersect
atmosphere
oceans
Rate
affected by
T difference
between
heat source
convective fluid
Effectiveness
heat transfer
dependant
heat source placement
mass movement
particles
w/in a system
distance
Can be considerable
Conduction
Heat transfer
Particle collision
no net movement
particles
Hotter further vibrate
collisions
energy transfer
Thermal conductivity
energy flow/ second
area 1sqm
thickness 1m
per °T
difference between
material ends (2)
Units
Heat conductors
Solids best
heat insulators poor
Calculations
Energy/second
Temperature difference
Flow
Hot to cold
final value ↓ initial
∴ always -
Final Equation
Symbols
Energy change
ΔQ
Always -
Area (variable)
A
Distance travelled
d
Thermal conductivity
k
Must be specified
different each substance
∵ physical structure
Radiation
does not
involve particles
need a medium
Electromagnetic radiation
all objects emit
except at 0K
Source
moving charged particles
faster movement, hotter substance
occurs through
electromagnetic waves
Temperature, kinetic
Kinetic
Particle model
All matter
particles
constant motion
have kinetic energy
collisions btw/ elastic
potential energy
depends
distance between particles
stored in
springs connecting particles
Particles
solids
bound
liquids
loosely bound
gases
bonds broken
energy possessed
body
due to motion
Temperature
Avg.
Random kinetic energy
particles in a body
R/ w/
heated material
avg. kinetic energy ↑
material heated
+heat energy added
increase proportion
vibrating atoms
∴ temp ↑
