1. Please take your notebook out and take your hats off Science 14 and 10-4 with Mrs. Martin 5.5 Heat Transfer Technologies

2. Agenda Review Notes on 5.5 Heat Transfer Technologies – Liquid coolant in engines – Refrigerators Videos

3. Review Particle Model of Matter says: – All matter is made up of small particles. – All particles are in constant motion. What is this jiggling or vibrating motion called?

4. Review Brownian motion is the jiggling or vibrating of particles As the temperature increases what happens to the movement of the particles? Temperature is the average of all kinetic energies (motion).

5. Review Give an example of: Convection – hot liquid or gas rises Conduction – direct contact heat transfer Radiation – travels in rays or waves

6. Heat Transfer Technologies Convection ovens use a fan to move the air in convection currents

7. Getting Rid of the Heat Engines get hot because fuel combustion releases heat Vehicles need to remove heat to protect the engine If the engine doesn’t cool properly, it overheats and explodes like this: https://www.youtube.com/watch?v=w9dED6 bNIpM https://www.youtube.com/watch?v=w9dED6 bNIpM

8. Video

9. Coolant Heat is conducted from the engine to the liquid coolant, which is pumped to the radiator

10. Radiator Metal alloy is a good conductor Heat from the liquid is conducted through this alloy to the air Either a fan or the motion of a vehicle forces the heat from the radiator into the air

11. Extra time? Video on how an engine works and is cooled: – https://www.youtube.com/watch?v=V7inC4lOpGs https://www.youtube.com/watch?v=V7inC4lOpGs – New technology https://www.youtube.com/watch?v=xeYPR-v_9Ko https://www.youtube.com/watch?v=xeYPR-v_9Ko

12. Evaporation When you sweat, it is so that the water can evaporate to cool your body Water absorbs the heat and removes it when it evaporates into the air

13. Like liquid coolant in an engine, a refrigerator uses refrigerant as coolant. Coolant circulates through the pipes Refrigeration

14. Heat from the hot food goes to the cold refrigerator air The coolant evaporates as it gets warmer It is pumped to the compressor and is converted back to a cool liquid The heat is released to the room

15. How does leaving the fridge door make the room warmer?

16. What happens when cooling fails? What happens if the electricity goes out in a nuclear power plant? – https://www.youtube.com/watch?v=91JZCbGLCvk https://www.youtube.com/watch?v=91JZCbGLCvk – (short on time go to 2:55-4:15) Nuclear reactor meltdown from cooling malfunction on the NEWS: – https://www.youtube.com/watch?v=ulO9LOQ0yis https://www.youtube.com/watch?v=ulO9LOQ0yis

17. Quick Quiz #2 ___________ #1 ___________ #3 ___________