IZhO 2013 — Задача 2. Part 2. Fresnel mirror

*IX International Zhautykov Olimpiad/Experimental Competition

EXPERIMENTAL COMPETITION 16 January, 2013

Please read the instructions first: · 16 януари 2013 г.*

Условие

In the following parts of the problem estimation of errors is not required!

Using a piece of plasticine attach the plate with the optical elements to the lens, i.e. use the lens as a stand only. Place the lens with the plate between the guide rulers such that the laser beam directly hits the Fresnel mirror. Place the laser with the screen at a distance of 15-20 cm from the mirror. Carefully adjust your installation such that the laser beam moves along the mirror diameter when the mirror itself is displaced. You should see the diffuse reflected spot which should move almost horizontally at the level of the incoming laser beam when the mirror is slightly displaced. The Fresnel mirror is a set of concentric rings whose radii vary with the number $k$, counted from the center, according to the law $r_k = r_0 k^{\gamma} \quad (1)$ In this part of the problem deflection angles cannot be considered small.

2.1 Measure the displacement of the center of the reflected spot $\Delta x_1$ as a function of the mirror displacement $x$. Plot the graph of the sine of the reflection angle as a function of the mirror displacement.

2.2 Estimate $\gamma$ in formula (1).

Отговори

Решение

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Оригинал в Архива: IZhO_2013_Exp_eng_fiz.doc