1. 14-6 Latent Heat Latent Heat *Latent heat is heat required to make a state change occur…there is no temperature change. *Q=mL …. Where L is a latent heat value you would look up on a chart and m is mass. *see pg 425 chart. * See Examples 14-8 and 14-9

2. Heat Transfer: Conduction The 3 types of heat transfer are conduction, convection, and radiation Conduction is the movement of heat by direct contact. [ D Q/ D t]=(kA) [(T 1 -T 2 )/l] see pg 429 for k Conductors carry heat well, insulators not so well. k is the thermal conductivity constant See Example 14-11

3. 14-8 Heat Transfer: Convection Convection is the movement of heat in fluid currents. Forced convection is man-made…fans, AC, Central heat etc…

4. Heat Transfer: Radiation *Radiation is the movement of heat as infra-red, electromagnetic radiation. (D Q/ D t)=e s AT Stefan-Boltzmann equation s = Stefan-Boltzmann constant e= 5.67x10 -8 W/m 2 K 4 = emissivity (D Q/ D t)=e s A(T 4 1 – T 4 2 ) Net flow of radiation See example 14-13 and 14-14 p434/435 1350W/m 2 is the solar constant. (D Q/ D t)=(1000W/m 2 ) eAcos Q 1000W/m 2 ) actually reaches Earth’s surface.

5. Homework Due Friday EOP 22-24,28,32-36,40 page 439/440 Test Monday