[jokes] truyen cuoi sinh vie^n Nga again

[Dam Son <son@u.washington.edu>]

Sinh vie^n Nga na`o cu~ng pha?i ho.c mo^n Pho`ng ve^. da^n su+. dde^? 
dde^` pho`ng tru+o+`ng ho+.p chie^'n tranh.  Trong mo^.t buo^?i ho.c mo^n
na`y, mo^.t dda.i ta' gia?ng:

"Gia? su+? va^.n to^'c vie^n dda.n dda.i ba'c khi bay ra kho?i no`ng pha'o
la` V, va` go'c giu+~a no`ng pha'o va` ma(.t dda^'t la` alpha.  Khi ddo'
ta^`m ba('n, tu+'c la` khoa?ng ca'ch giu+~a ddie^?m vie^n dda.n ro+i
xuo^'ng dda^'t va` ddie^?m vie^n dda.n ddu+o+.c ba('n ddi, la` (vie^'t
le^n ba?ng)

             2
            V
           ---- * sin (alpha)
            g

trong ddo' g la` gia to^'c tro.ng tru+o+`ng."

Mo^.t sinh vie^n gio+ tay ho?i:

- Thu+a ddo^`ng chi' dda.i ta', nhu+ va^.y kho^ng the^? ddu+o+.c, vi` gia? 
su+? no`ng pha'o hu+o+'ng vuo^ng go'c vo+'i ma(.t dda^'t, tu+'c la` go'c
alpha ba(`ng 90 ddo^, thi` ta^`m ba('n pha?i ba(`ng kho^ng, trong khi theo
co^ng thu+'c tre^n ba?ng thi` ta^`m ba('n la.i kha'c kho^ng.

Dda.i ta' nhi`n co^ng thu+'c, nga^~m nghi~ mo^.t lu'c ro^`i no'i:

- Go'c alpha giu+~a no`ng pha'o vo+'i ma(.t dda^'t kho^ng the^? ba(`ng 90
ddo^. ddu+o+.c, vi` kha^?u pha'o co' ca'i nga.nh cha('n, no`ng pha'o chi? 
na^ng ddu+o+.c le^n 80 ddo^. la` he^'t co+~.