1. Raising Temperature
by adding heat
§ 16.5

2. Specific Heat (Capacity)
Heat needed to change the temperature of a unit amount of a substance.
c = q
mDT
q = heat input
m = mass of sample
Dt = temperature change
Units: J/(kg K) or cal/(kg K)
Intensive

3. Heating Mechanisms
it’s really all work
§ 16.6

4. Heating Heat is transferred between objects by:
Conduction: collisional transfer of kinetic energy
Convection: buoyancy-driven fluid circulation
Radiation and absorption of electromagnetic waves

5. Conduction
Conductivity varies with material; solids > liquids > gases

6. Conduction Fourier conductivity law Q = kA(DT/L)t where
Q = heat transferred
A = cross-sectional area
DT = temperature change
L = length
t = time

7. Convection Warm fluids expand, becoming less dense
Circulation is driven by buoyancy forces
Much faster than conduction

8. Convection
Convection drives the weather!

9. Radiation Power output increases as T4.
Objects are heated by absorbing radiation.
Objects are cooled by emitting radiation.