1 WOMEN AND MINORITIES IN SCIENCE ……….AND OUR ALLIES “D’ou venons nous? Ou sommes nous? Ou allons nous?” (Gaughin) 1st Meeting : Monday September 13 3:45 in 1033 Lounge LGRC We’ll figure out what we want the group to do. Some ideas are: --SNACKS AND CHATS --Practice giving talks and asking questions in front of other people --Discussions with seminar speakers and other guests -- Plan for a public affairs radio show on the topic of women and minorities in science (WMUA) --Working with middle school students on math and science --Discussing how to get involved in research Questions and feedback—Professor Jennie Traschen, 1127B LGRC [email protected] 2 Sep. 10, 2010! assignments: intro to OWL, math review, statistical gas readings: Ch. 1 & 2, Ch. 3.1-3.4 3 Chapter 2: A statistical gas We begin by considering a collection of particles that have the following characteristics: • They don’t stick (no attractive or repulsive forces) • They have only kinetic energy (no force fields) • They have zero volume This is how we define an ideal gas. 4 Gas particle dynamics Let’s consider a single gas particle of mass m in a box with square sides of length ℓ. The particle moves with speed u. !x y z ℓ ℓ ℓ m What is the average pressure P exerted by the particle on a wall of the box?!5 ℓ ℓ x y ux uy 6 7 8 Many particles: an ensemble9 10 11 Single particle pressure: summary 12 Ideal Gas Robert Boyle & Jacques Charles:!slope ≅ 8314 J mol-1 K-113 Ideal Gas law No potential energy Only elastic collisions Zero particle volume van der Waals gas law 14 Internal energy, E For an ideal gas, the only energy is the kinetic energy of the particles. The sum of all the particles’ K.E.s represent the internal energy E of the gas.!15 Chapter 3: Energy and the First Law • Systems and their energetics • Internal energy E • Work w and heat q • Heat capacity C • Latent heat L 16 Thermodynamic systems System: a specific collection of molecules, fields and space Surroundings: the part of the Universe that is not the system System Universe17 The ideal gas as a system PV=nRT Surroundings: could be a water bath, the rest of the atmosphere, a metal bar, etc. Ideal gas Universe 18 States and equations of state PV=nRT Ideal gas 19 First Law of thermodynamics The net change in the energy content of a system and its surroundings is zero. System Universe 20 Change in E for a system q = heat into system!w = work on system!init!fin!Einit Efinal ΔE = Efinal - Einit = q + w