# Day 01

## 1.2 1D heat conduction

heat and thermal energy, agitation

conduction (convection)

simplest case we can think of: slender rod

thermal energy density e(x,t)

### Energy

units Joule (J) examples: mgh, 1Ws, 1 Amp across 1 Volt for 1 sec

what happens in a chunk over time

### Conservation law

conservation of energy, heat flux φ(x, t)

conservation law in terms of e and φ

all as integral

a snag with energy density: temperature [neglected to take board photo]

Objects of two different materials in equilibrium with each other will generally have different energy densities (think chunks of steel and styrofoam). This leads us to invent a new measure of thermal energy called temperature such that "temperatures" of objects in equilibrium have the same value.

Got to here, Jan 31, 2017.

# Day 02

Objects of two different materials in equilibrium with each other will generally have different energy densities (think chunks of steel and styrofoam). This leads us to invent a new measure of thermal energy called temperature such that "temperatures" of objects in equilibrium have the same value.

## Temperature

volumetric heat capacity

specfic heat capacity

absolute zero

What is the thermal energy content of this brass rod (relative to absolute zero)?

## Fourier's "Law" (approximation)

Heat energy flows from hot to cold - let's linearize in the temperature gradient!

## 1.4 Equilibrium solutions

### Prescribed value

Got to here, Feb 2, 2017.