couples of things to discuss, left atened of session

anyways back to ch.15

this chapter si related to laws of thermodynamics

we’ve dealing with this topic indirectly since ch.13 really

there are things that we talked about in ch13

• ideal gas, consider with certain pressure and volume adn temp
  • and then we changed volume
  • we increased pressure
  • temp
    • what happens?
  • we used the law of ideal gas to find this

but int his process, there are unaddressed things

• compression of gas → we used formula to identify the numbers
  • but what happened in terms of heat exchange?
  • if you compress an ideal gas, heat might be gained or lost depending on the medium
  • if the system is completely isolated, just by compressing an ideal gas, can heat be created?

ch15 will discuss about this (behind the scene of the ideal gas law)

U (internal energy) → sum of all energy that a molecule has

• kineitc, potential, etc
• when you have an ac, and some of the molecuels go upward toward the celining, they gain potential energy
  • going upstair to roof, and carry a ball with you
    • and release the ball from roof. it falls down
      • why? bycarrying it up, we carried potential energy which is being released as kinetic energy