IYPT 1993, Задачи на турнира — Задача 9–10. Gun

Problems for the 6th International Young Physicists’ Tournament

Critical edition

Protvino, Russia; June 18‒25, 1993 [1]

Critical edition: corrected and commented official translation [2]

FINAL DRAFT. — Please do not re-publish. Suggestions and criticism welcome

Edited and commented by Ilya Martchenko. The original edition’s historical notes, sources and acknowledgments are retained with problem 1.

Условие

The picture shows an electromagnetic gun circuit. It can launch metal rings. [7]

(S, C, K) is a power supply consisting of

S, a source of constant voltage in the range 10‒300 V, [8]

C, a capacitor with $C=1000\,\mu\mathrm F$,

K, a switch;

L is an induction coil;

F is a ferromagnetic core;

R is a metal ring projectile with mass from 1 to 100 g.

$C_n$ is a converter (some device that converts the energy passing from the capacitor to inductance L in a way you need.) This element does not contain energy sources. It may be completely absent from your gun.

You are to construct, make and demonstrate the electromagnetic gun. It is worth mentioning that the demonstration of your gun will take place with the power supply (elements S, C and K) presented by the Organizing Committee of the YPT. [9] Develop two variants of the gun: [9]

9. A long-range gun is to be constructed to shoot a ring to a maximum altitude. [10] The control parameter is the quantity $H=kh/U^2$, where $k=10000\,\mathrm{V^2}$, [11] h is the height of the projectile, U is the voltage to which the capacitor is charged.

10. A gun-lift is to be constructed to achieve the maximum work of lifting [12] a weight (ring). The control parameter is $W=mgh$, where m is the mass of the ring, $g=10\,\mathrm{m/s^2}$.

Note [7]

The abbreviations used in the legend are identical in 1993 English, in Slovak, in 1996 Czech and in 2006 English versions. The figure is apparently re-drawn in the Slovak and the 2006 English texts. The abbreviations used in the legend are different in the Hungarian version. The 1993 English figure and characters are reproduced in this document

Note [8]

“V is source of constant voltages of 10 V and 30 V, that you can switch between”, according to the Hungarian text

Note [9]

These two sentences are missing in the Slovak text

Note [10]

“To achieve the maximum height of the ring”, according to the 1993 English text

Note [11]

“where k is the proportionality factor equal to $10000\,\mathrm{V^2}$“, according to the Hungarian text. It should be noted that no comments on what is V is anywhere given

Note [12]

“To perform maximum work when moving a projectile (a metal ring)”, according to the Slovak text

Решение

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Оригинал в Архива: 1993.pdf