5.251. t = (i3 — 1) cpd/18crT: = 3 hours, where c is the specific heat capacity of copper, p is its density.
5 252. T2 == T1 d121= 0.4 kK.
5.253. (a) Cv = (OU/OT)v =16 aT3VIc=3 nJ/K, where U=
.4aTIVIc; (b) S = 16crT3V/3c = 1.0 nJ/K.
5.254. (a) cop,. = 3Tla = 7.85.10" s-1 ; (b). X•pr = 2nca/5T =
= 1.44 ti,m.
5.255. (a) u. = (kT 17E20)(02; (b) u. = (h/n2c3) (03 e-5(047'.
5.256.
—
ieuclh
vs
— 2 /kTi,i
167C2Cnk-3
•
c3
e 22-thvillT — 1
afic
5.257. AP = 4n2c2hT50%/b6 (e2nitc/kb• 1) = 0.31 W/cm2, where
b is the constant in Wien's displacement law.
5.258. (a) 1.1 [tm; (b) 0.37; (c) P2 /P1 =--- (T 2/T1)4 (1 — Y2)/(1—Y1) =
= 4.9.
5.259. rc. dm —
co2 dw
dX
8a-4
T
1
oo elm' hr
• -
e2nhoira,
5.260. (a) (j) = Pk181c2chr2 = 6.1013 cm-2s-1;
(b) r = VP2t./2An/2ric = 9 m.
5.261. dpIdt = (De/c.
5.262. (p) = 4 (1 -I- p) Elnd2c-r
50 atm.
5.263. p = (Etc)
p2 -I- 2p cos 20 = 35 nN • s.
5.264. p = (17c) (1 + p) cost 0 = 0.6 nN/cm2.
5.265. F = nR2Ilc = 0.18 IAN.
5.266. F = P/2c (1 + 12).
5.267.(
p
(b)
-
a) Ap
2hw • I 1 —02
A
P=
2hw
Here R=
1-0 •
= V/c. It is evident that in the reference frame fixed to the
mirror the latter obtains the smaller momentum.
5.268. sin (8/2) Elmc F, 0 = 0.5°.
5.269. Doi/coo = — (1 — e-vm/Rc2) < 0, i.e. the frequency of
the photon decreases.
5.270. V = 23-thc (1 — 1/11)/eAk = 16 kV.
5.271. V = nhcled sin cc = 31 kV.
5.272. ?min = 2Tih/mc (y —1) = 2.8 pm, where v =1 /17.1 — (v/c)2.
5.273. 332 nm, 6.6.105 m/s.
5.274. A— 2Ttch (1 ,12-2'21) '1) =1.9 eV.
5.275. Tmax
4.4 \ 7
( 1 I )
5.276. Tmax = h ((Do + (0) — Af = 0.38 eV.
5.277. w = 2nchTleA, = 0.020.
5.278. v„.4„x = 6.4.105 m/s.
5.279. 0.5 V; the polarity of the contact potential difference
is opposite to that of external voltage.
5.280. hlmc, the Compton wavelength for the given particle.
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