TEMPERATURE ( What is it?) Date___________ Temperature is a measure of___________________________________ ____________________________________________________________ Total KE of all of the RP of a sample Kinetic energy(KE) is the energy of motion Random (in all directions) Motion of RP’s is: 1. ___________________________________ 2.____________________________________ At different speeds (centered on the average) Pool table analogy - Start with all at rest Strike the que and hit the front ball of the pack All balls start to move/ collide with each other and the walls of the table Eventually the balls come to a stop Their KE was transformed into thermal energy. (INELASTIC COLLISIONS*) Elastic vs. Inelastic collisions- KE is not conserved * ElASTIC COLLISIONS: KE is conserved…. The particles have same speed before and after collision OR…. If one slows down, one must speed up.

Is the speed of all RP’s in a sample the same? Yes/No RP’s have a distribution of speeds Maxwell-Boltzmann Distribution # RP’s Speed (m/s) 100 200 300 400 500 Most probable speed Few here Few here

How are temperature and KE related? Distribution of RP with respect to speed/ KE in a sample KE = ½ mv2 Maxwell-Boltzmann Distribution # RP’s Speed (m/s) 100 200 300 400 500 # RP’s Kinetic Energy (J/RP) Distribution of RP’s with respect to KE How are temperature and KE related? https://ch301.cm.utexas.edu/simulations/js/idealgaslaw/

Temperature and Maxwell- Boltzmann Distribution For a given sample ( a collection of billions and billions of RP’s) ‘hotter” =_________________________________ Know…. Temperature – Increases OR decreases OR stays the same Kinetic Energy – of the RP Increases OR decreases OR stays the same on average, the RP__________________ or, more __________________________ and fewer move_____________________ Thermal energy increases Moves faster Move faster Move slower # RP’s Kinetic Energy (J/RP) KEavg KEavg

Temperature and Maxwell- Boltzmann Distribution For a given sample ( a collection of billions and billions of RP’s) ‘hotter” =_________________________________ Know…. Temperature – Increases OR decreases OR stays the same Kinetic Energy – of the RP Increases OR decreases OR stays the same on average, the RP__________________ or, more __________________________ and fewer move_____________________ Thermal energy increases Moves faster Move faster Move slower # RP’s Kinetic Energy (J/RP) KEavg Thermal energy decreases Colder” =_________________________________ Know…. Temperature – _____________________ Kinetic Energy –of the RP _________________ on average, the RP__________________ or, more __________________________ and fewer move_____________________ “colder” decreases KEavg decreases move slower move slower “hotter” move faster

Measuring Temperature Temperature is some measure of __________________________________________________________________________ The thermal energy of a sample that is reflected in the distribution of KE of RP KE = ½ mv2 # RP’s Kinetic Energy (J/RP) Distribution of RP’s with respect to KE To measure the KE of a sample directly one would_____________________________________________________ Measure the mass and speed of Each RP! IMPOSSIBLE, RP are to small to measure Temperature is our indirect measure of thermal energy. We measure temperature using__________________ Thermometer