Irodov – Problems in General Physics

(Joyce) #1

5.281. Let us write the energy and momentum conservation laws
in the reference frame fixed to the electron for the moment preceding
the collision with the photon: hco moc 2 &plc = my, where


m = mo 1/ 1 — (v/c)^2. From this it follows that v = 0 or v = c.
The results have no physical meaning.
5.282. (a) Light is scattered by the free electrons; (b) the increase
of the number of electrons that turn free (the free electrons have the
binding energy much lower than the energy transferred to them by
the photons); (c) the presence of a non-displaced component is due
to scattering by the strongly bound electrons and the nuclei.
5.283. a = 42dc [sin (0 2 /2) — t1 sin (0^1 /2)1/(1 — 1) = 1.2 pm.
5.284. T = hcoril(1 i) = 0.20 MeV.
5.285. (a) e.)' = 2nc/(k 2nh/mc) = 2.2.10 20 rad/s;
2nch/X
(b) T — 1+ Xmc 12rch 60 keV.


hco
5.286. ho)' = 1+2 (h(o/mc 2 ) sin (0/2) 0.144 MeV.

5.287. sin (0/2) =1/ mc (p — p')I2pp'. Hence 0=120°.
5.288. hu) = [1 +V 1 + 2mc 2 IT sin 2 (0/2)] T/2 = 0.68 MeV.
5.289. = (2mh/mc) (1/1 + 2mez/T,,,ox— 1) = 3.7 pm.

5.290. tan

1/4h/mcA— 1
cp

n A.

1+hoon, 2 , (^) 31°.
5.291. p
=21 (1+ ri)
(1 ± 211) 03
=.
3.4 cm.
5.292. A?. ---- (4hImc) sin^2 (0/2) = 1.2 pm.
6.1. r = 3e 2 /2E = 0.16 nm, 2 = (2acle) y mr 3 = 0.24
6.2. b = 0.73 pm.
6.3. (a) rmin = 0.59 pm; (b) rm i n = (2Ze^2 I T) (1 -1- mc,ImLi)
0.034 pm.
6.4. (a) pmin = (Ze 2 /T) cot 2 (0/2) = 0.23 pm; (b)^ rmin =-_
[1 cosec (0/2)1 Ze^2 IT = 0.56 pm.
6.5. p;---e, 2 1/2mT/[1+(2bT/Ze 2 ) 2 1.
6.6. T e=mpe 4 Imeb 2 T = 4 eV.
n sin (0/2)
6.7. b — where n =1/1 +Uo/T.



  • 1/ 1+ n 2 — 2n cos (0/2)
    6.8. (a) cos (0/2) = b/(R r); (b) dP = 1 / 2 sin 0 d0; (c) P
    = 1/2.
    6.9. 3.3-10-5.
    6.10. d = (4Jr 2 T 2 /nIZ 2 e 4 ) sin 4 (0/2) = 1.5 p,m, where n is the
    concentration of nuclei.


6.11. Zpt = ZAg T1APt/AAg = 78.
6.12. (a) 1.6.10 6 ; (b) N = and (Ze 2 I T) 2 cot 2 (0 0 12) IOv = 2.0.10^7 ,
where n is the concentration of nuclei.
6.13. P = and (Ze^2 /mv^2 )^2 = 0.006, where n is the concentration
of nuclei.
6.14. ANIN = 1 — nnZ^2 e^4 /T^2 tan^2 (0^0 /2) = 0.6.

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