PHY 101 Lecture Notes - Lecture 1: Thermal Expansion, Boiling Point, Junkers J 1
a=b=c
no net heat will flow between the objects
what determines direction of heat transfer?
differences in temperature
temperature is proportional to
average kinetic energy of materials that make up the substance
farenheit, celsius, kelvin:
absolute zero
freezing point of water
boiling point of water
-460, -273, 0
32, 0, 273
212, 100, 373
absolute zero
theoretical temp at which there is no thermal energy
farenheit=
(9/5)(celsius)+32
celsius=
(5/9)(farenheit-32)
thermal expansion
change in temperature of most solids results in a change in their length
find more resources at oneclass.com
find more resources at oneclass.com
when temperature of an object changes, its length changes (equation)
a lot
alphaLdeltaT
alpha---coefficient of linear expansion
change in volume re: temperature equation
betaVdeltaT
beta--coefficient of volumetric expansion
types of systems
closed, isolated, open
closed system
capable of exchanging energy, but not matter, with the surroundings
ex. gases in vessels with movable pistons
isolated system
very rare. cannot exchange matter or energy with the surroundings
ex. bomb before it goes off, entire universe (because no surroundings)
open system
can exchange matter and energy with the surroundings. ex. boiling water, human being, combustion
state functions vs. process functions
state functions--independent of the path taken to get to a particular state.
find more resources at oneclass.com
find more resources at oneclass.com
measurement of something at a current state
ex. pressure, density, temp, volume, enthalpy, entropy
process functions--describe path taken to get from one state to another
ex. work, heat
first law of thermodynamics
change in total internal energy of a system=amount of energy transferred in the form of heat to a
system-amount of energy transferred from the system in the form of work
essentially--energy cannot be created or destroyed, only changed in form
work--positive and negative values
positive work--work is done by the system (expansion)
negative work--work is done on the system (compression)
only two processes where energy can be transferred from one object another
work and heat
second law of thermodynamics
objects in thermal contact and not in thermal equilibrium will exchange heat energy such that the object
with a higher temperature will give off heat energy to the object with a lower temperature until both
objects have the same temperature at thermal equilibrium
energy spontaneously disperses from being localized to being spread out if it is not hindered from doing
so
heat
find more resources at oneclass.com
find more resources at oneclass.com
