IYPT 1998, Задачи на турнира — Задача 16. Strange motion

11th IYPT (1998)

Заглавие в източника

Sources: Official version 97/10/15, Prouza 10-20-1997, Školská fyzika, 1996/1997, 3, 71—72, Vlado Koutny ca. 1999
Selected at the Preparatory Seminar in Germany on Oct. 15, 1997
Exemplary solutions for 1998 →

Условие

Make a mixture of ammonium nitrate and water, proportion 5 to 1. When the mixture is heated to about 100 °C it melts. When it cools, it crystallizes and you may observe a strange motion below the surface. Investigate and explain the phenomenon. Safety rules: Do not heat the ammonium nitrate without water, preferably use a water bath! Use protection glasses during the experiment!

Решение

---

Оригинал в Архива: 1998.txt