# The Ungerecht Family Tree

urp:physheat

## Heat

Specific heat = ratio of the quantity of heat that we require to raise the temperature of a body by one degree compared to doing the same of an equivalent mass of water.

Also, we use the term in a narrower sense to mean the amount of heat, in calories that we require to raise the temperature of one gram of a substance by one Celsius degree.

Q = m * c * ΔT,

```c = specific heat, units of J / (kg * k),  (k = kelvin)
Q = heat energy, in Joules ... or "transfer of heat"```

combining masses with different temperatures:

```tf = (m1*c1*t1 + m2*c2*t2 + ... ) / (m1*c1 + m2*c2 + ...)
tf = temperature final
(see https://www.engineeringtoolbox.com/temperature-mixing-liquid-solids-d_1754.html)```

Thermal conductivity K in watts/(meter * kelvin):

```K = (Q * d) / (A * delta T)
A= surface area, in square meters
d = distance between planes / thickness of material```

rate of heat conduction = Q/t

```Q/t = (K * A * deltaT) / L
A = area of cross section, L = length of material
K = thermal conductivity```

For two materials that are joined, see the temp at the middle by setting Q/t of one item to another (see https://physics.gurumuda.net/heat-transfer-conduction-problems-and-solutions.htm)

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