Introduction to Physical Science Monday, Wednesday, Thursday Tom Burbine [e-mail]

1
Introduction to Physical ScienceMonday,
Wednesday, ThursdayTom Burbinetomburbine_at_astr
o.umass.edu
2
Thermal energy (kind of kinetic energy)?

• Temperature is a measure of the average kinetic
  energy of the particles
• Higher temperature more kinetic energy,
  particles moving faster
• For examples, air molecules around you are moving
  at 600 m/s

http//eo.ucar.edu/webweather/molecules.html
3
Temperature scales

• In America, we use Fahrenheit
• Water freezes at 32 degrees F
• Water boils at 212 degrees F
• Everywhere else, they use Celsius
• Water freezes at 0 degrees C
• Water boils at 100 degrees C

4
In Science

• Temperature is usually given as Kelvin
• Zero Kelvin is absolute zero nothing moves
• Add 273.15 to the Celsius temperature to get the
  Kelvin temperature
• 273.15 Kelvin 0 degrees Celsius

5
(No Transcript)
6
(No Transcript)
7
Absolute Zero

• 0 Kelvin
• Lowest limit of temperature
• Molecules have lost all available kinetic energy

8
Heat

• Heat is thermal energy in transit
• Objects contain thermal energy (not heat)
• Thermal energy flows from high temperature
  substances to low temperature substances

9
Heat

• Use Joules

10
First Law of Thermodynamics

• Energy can be neither created nor destroyed. It
  can only change forms.
• Or
• The change in the internal energy of a system is
  equal to the amount of heat supplied to the
  system, minus the amount of work performed by the
  system on its surroundings.

11
Second Law of Thermodynamics

• Heat never spontaneously flows from a cold
  substance to a hot substance

12
Third Law of Thermodynamics

• No system can reach absolute zero.

13

• http//www.youtube.com/watch?vKTHiIwxcexI

14
Any Questions?