dn( +13+12 d v. av. av a√r exp 3k T Known v C dn(vr, vy, v)3 whule C N 2
( ) exp d d d 1 d ( , , ) 2 2 2 2 3 x y z x y z x y z v v v v v v N n v v v + + − = = ? m k T v 3 2 B Known = 2 2 2 2 d ( , , ) 3 = = N n v v v v v while x y z
dr mlv+.+ exp d v..av 2R B 2KT For unit volume dnlvx,y7 m(2+n2+2) =no 2kBT expI d v dv.av ckpT Maxwell velocity distribution
( ) ( ) x y z x y z x y z v v v k T m v v v k T m N n v v v d d d 2 exp 2 d , , B 3 2 2 2 2 B + + − = For unit volume d ( , , ) x y z n v v v Maxwell velocity distribution ( ) x y z x y z v v v k T m v v v k T m n d d d 2 exp 2 B 3 2 2 2 2 B 0 + + − =
dn(v) exp 4πv2dv 2TRB nof(v)vdv Maxwell speed distribution Most probable speed For one molecule, what speed is most possible? Among N molecules, what is the speed most molecules have in unit interval?
v v k T m v k T m n v n 4 d 2 1 exp 2 d ( ) 2 B 2 3 2 B 0 − = Maxwell speed distribution For one molecule, what speed is most possible? Most probable speed n f (v)4 v dv 2 0 Among N molecules, what is the speed most molecules have in unit interval?