1 / 34

Atoms and heat

Atoms and heat. “Absolute zero” refers to: The size of atoms A new form of energy Motion stopping A fighter jet A type of collision. Bose-Einstein condensation. Temperature = 170 x 10 -9 K = 170 nK. The average speed of the molecules in your desk is approximately: 2 inches/s [5 cm/s]

oren
Download Presentation

Atoms and heat

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Atoms and heat

  2. “Absolute zero” refers to: • The size of atoms • A new form of energy • Motion stopping • A fighter jet • A type of collision

  3. Bose-Einstein condensation Temperature = 170 x 10-9 K = 170 nK

  4. The average speed of the molecules in your desk is approximately: • 2 inches/s [5 cm/s] • 1 ft/s [0.3 m/s] • 3 ft/s [1m/s] • 1000 ft/s [330 m/s] D) 900 million ft/s [300 million m/s]

  5. August 6, 2010

  6. Energy content of various sources

  7. Temperature scales

  8. Think back to the electrolysis we did last week. We made H2 and O2. Which molecule has a faster speed at room temperature? • Hydrogen • Oxygen • They’re the same speed

  9. Moral of the tanker story? • Heat can melt containers • Use caution when transporting flammable materials • Pressure is proportional to temperature • Solids are much heavier than liquids • High internal pressure needs to be let out

  10. Donut-shaped piece of metal. What happens to the hole if I heat this? • It gets bigger • It gets smaller • It stays the same size

  11. y x What about a flat bar – if I heat it, will it expand more distance in the x or y direction? • x direction • y direction • same in both directions

  12. Donuts again… Donut-shaped piece of metal. What happens to the hole if I heat this? • It gets bigger • It gets smaller • It stays the same size

  13. Water seems to behave similar…

  14. But it has strange behavior…

  15. Density of water

  16. Sea level rise predictions From wikipedia, referencing IPCC report 2009

  17. Tues 14 Sept

  18. Are you freaking out about tomorrow’s exam? • Not really • Sort of • Feeling confused on some stuff • Need to spend today getting seriously organized • Panic

  19. What time of the year would you expect to get the best gas mileage out of your vehicle? A. Summer B. Winter C. About the same for both Why?

  20. Which of the following are a heat engine? A) A coal fired electric generator B) A car engine C) A steam engine in an old fashioned train. D) A nuclear power plant's turbines E) All of the above

  21. Suppose the gas of atoms bouncing around in the picture has a temperature of 25 C (about room temperature). How does the pressure on the walls change if I heat up the gas to 100 C? • Goes up by a factor of 4 • Goes down by a factor of 2 • Goes up by a factor of 25% • Goes up by a factor of 50% • Stays the same

  22. Additional clickers (not used)

  23. If the temperature of the earth increases, a significant cause of the sea levels rising besides melting glaciers and ice would be: • Additional rainfall • More oil spills • Thermal expansion of water • The increased evaporation of water

  24. It’s summer, and you accidentally left your window open on a hot day. You are letting: • Hot air come in • Cold air go out

More Related