I WB | Temat: Wyznaczenie stałej Plancka oraz pracy wyjścia elektronu |
23.04.2008 |
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Nr cw. 9 | Marek Nalepka |
Nr filtru |
Długośc fali λ [nm] | Szerokość połówkowa τ [nm] | Częstotliwość fotonu | napięcie hamujące [mV] |
---|---|---|---|---|
[nm] | [nm] | [1/s] | Uśr | |
1 | 368 | 10 | 8,152 | 949 |
2 | 373 | 10 | 8,043 | 930 |
3 | 405 | 20 | 7,407 | 767 |
4 | 417 | 6 | 7,194 | 641 |
5 | 428 | 10 | 7,009 | 581 |
6 | 440 | 10 | 6,818 | 536 |
7 | 445 | 10 | 6,745 | 490 |
8 | 452 | 10 | 6,637 | 451 |
Częstotliwość fotonu $\nu = \frac{c}{\lambda}\ \left\lbrack \frac{1}{s} \right\rbrack$
c – prędkość światła
λ − dlugosc fali
$v_{1} = \frac{300000000}{0,000000368} = 8,152$ v2 = 8, 043 v3 = 7, 407 v4 = 7, 194 v5 = 7, 009
v6 = 6, 818 v7 = 6, 742 v8 = 6, 637
Obliczam $\frac{1}{\lambda}$
$\frac{1}{\lambda_{1}} = 2,717 \times 10^{6}\ $ $\frac{1}{\lambda_{2}} = 2,681 \times 10^{6}$ $\frac{1}{\lambda_{3}} = 2,469 \times 10^{6}$ $\frac{1}{\lambda_{4}} = 2,398 \times 10^{6}$
$\frac{1}{\lambda_{5}} = 2,336 \times 10^{6}$ $\frac{1}{\lambda_{6}} = 2,272 \times 10^{6}$ $\frac{1}{\lambda_{7}} = 2,247 \times 10^{6}$ $\frac{1}{\lambda_{8}} = 2,212 \times 10^{6}$
Współczynnik a i b za pomocą regresji liniowej
$$a = \left\lbrack 8 \times \sum_{i = 1}^{8}{U_{i}\left( \frac{1}{\lambda} \right)_{i}} - \left( \sum_{i = 1}^{8}U_{i} \right)\left( \sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i} \right) \right\rbrack \times \frac{1}{X}$$
$$b = \left\lbrack \left( \sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i}^{2} \right)\left( \sum_{i = 1}^{8}U_{i} \right) - \left( \sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i} \right)\left( \sum_{i = 1}^{8}{U_{i}\left( \frac{1}{\lambda} \right)_{i}} \right) \right\rbrack \times \frac{1}{X}$$
$$X = 8\left( \sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i}^{2} \right) - \left( \sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i} \right)^{2}$$
$$\sigma = \sqrt{\frac{\sum_{i = 1}^{n}\left( U_{i} - a\left( \frac{1}{\lambda} \right)_{i} - b \right)^{2}}{n - 2}}$$
$$S_{a} = \sigma\sqrt{\frac{n}{X}}$$
$$S_{b} = \sigma\sqrt{\frac{\sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i}^{2}}{X}}$$
$$\sum_{i = 1}^{8}U_{i} = 5,345$$
$$\sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i} = 19,334\ \times 10^{6}\ $$
$$\sum_{i = 1}^{8}U_{i}^{2} = 3,833$$
$$\sum_{i = 1}^{8}\left( \frac{1}{\lambda} \right)_{i}^{2} = 46,988 \times 10^{12}$$
$$\sum_{i = 1}^{8}{U_{i}\left( \frac{1}{\lambda} \right)_{i}} = 13,178\ \times 10^{6}$$
X = 1, 267 × 1012
a = 0, 849 x 10 -6
b = 1, 537
σ = 3240
Sa = 0, 012 × 10−6
Sb= 0,38
Dla sprawdzenia obliczam współczynnik regresji liniowej $tga = \frac{U}{\frac{1}{\lambda}}$
$$tga = \frac{U}{\frac{1}{\lambda}} = \frac{431}{468,5} = 0,9198 \times 10^{- 6}$$
Stałą Plancka $h = \frac{a \times e}{c}$
$$h\ = \ \frac{0,849 \times 10^{- 6} \times 1,6 \times 10^{- 19}}{3 \times 10^{8}} = {5,932}^{- 34}$$
$$u\left( h \right) = \sqrt{\left( \frac{1,6\ x\ 10^{- 19}}{{3\ x\ 10}^{8}}\ x\ 0,012\ x\ 10^{- 6} \right)^{2}} = {6,23}^{- 36}$$
Niepewność u(U)= U×0,05
U1 = 0, 949 × 0, 05 = 0, 047 U2 = 0, 046 U3 = 0, 039 U4 = 0, 032 U5 = 0, 029 U6 = 0, 026 U7 = 0, 024 U8 = 0, 023
Niepewność $u(\lambda) = \ \frac{\tau}{2}$
$u\left( e\lambda_{2} \right) = \ \frac{10}{2} = 5nm$ u(λ3)=10nm u(λ4)=3nm u(λ5)=5nm
u(λ6)=5nm u(λ7)=5nm u(λ8)=5nm
Niepewność dla $\frac{1}{\lambda} = \ \sqrt{\left\lbrack \frac{1}{\lambda_{i} \times 10^{- 9}} \times u(\lambda) \times 10^{- 9} \right\rbrack^{2}}$
$\frac{1}{u\left( \lambda_{2} \right)} = 0,01$ $\frac{1}{u\left( \lambda_{3} \right)} = 0,03$ $\frac{1}{u\left( \lambda_{4} \right)} = 0,01$ $\frac{1}{u\left( \lambda_{5} \right)} = 0,01$ $\frac{1}{u\left( \lambda_{6} \right)} = 0,01$
$\frac{1}{u\left( \lambda_{7} \right)} = 0,01$ $\frac{1}{u\left( \lambda_{8} \right)} = 0,01$
Praca wyjścia elektronu ze wzoru W = e × b
b=1,537
$\overset{\overline{}}{W} =$ 1, 537 × 1, 6 × 10−19 = 2, 46 × 10−19J × s
$$u\left( W \right) = \sqrt{\left( \text{e\ x\ }S_{b} \right)^{2}}$$
$$u\left( W \right) = \sqrt{\left( 1,6\ x\ 10^{- 19}\ x\ 0,38 \right)^{2} =}4,76\ x\ 10^{- 20}$$