IYPT 1992, Задачи на турнира — Задача 3. The dam

Problems for the 5th International Young Physicists’ Tournament

Critical edition

Protvino, Russia, June 24‒July 1, 1992 [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

There is a saying in Russian, [8] “money goes like water through sand.” However, sand dams hold water. What should be the thickness [9] of the dam in order to retain water whose level [10] behind the dam is 10 m?

Note [7]

The Slovak text places here an entirely different problem No. 3 that reads:

  1. Floating ball

A ping-pong ball floats up from a depth x in a vessel with water.

  • Finally, the ball will jump out of water. What will be the altitude of the jump?

  • Describe the process of ascending if the vessel rotates about a vertical axis

Note [8]

Literally, “There is an expression, “money leaks out like water leaks through sand” in the 1992 Russian text

Note [9]

“How long has to be the barrier in order to retain the water with height 10 m above the surface”, according to the 2006 English version

Note [10]

“Depth” in [Kopelevich 1992], “level” in the 1992 Russian text

Решение

Внимание: Непълно решение

В архива няма официално решение на тази задача.

Оригинал в Архива: 1992.pdf