PHYS 2101 Lecture : Lecture 38
Document Summary
A new hw #14 is posted it"s due on tues night. However, there"s one additional posted, hw #15, which is optional (i"ll post the key right away because that material. Ideal gas law pv = nrt or pv = nkt. The internal energy (change) of an ideal gas depends only on the temperature (change) Special case: isothermal ( t=0) in the case of an ideal gas. Up to now, we"ve only considered monatomic gas . Every kind of molecule has a certain number f of degrees of freedom, which are independent ways of storing energy. Each degree of freedom has an energy 1/2 kt per molecule. Monatomic: 3 translational degrees of freedom f= 3 cv=3/2r. Diatomic: 3 trans + 2 rot degrees of freedom f= 5 cv=5/2r. Polyatomic: 3 trans + 3 rot degrees of freedom f= 6 cv=3r. Need to add in vibrations too! diatomic hydrogen gas . Because a gas is thermally insulated, or expansion/compression happens suddenly adiabatic.
