M. 298. Measure how long it takes for an ice cube, made of tap water, to melt if it is in a glass of tap water, which is at room temperature, and if it is in a glass of salt water (saline water), which has the same amount as the glass of tap water and also it is at the same room temperature. Repeat the measurements such that a small weight is frozen into the ice cube, and the cube is completely submerged in both the tap water and the saline water. It is worth dying the cubes with some food colour.
Deadline expired on 12 October 2009.