As illustrated beside there is a glass beaker inside a thermally insulated box. In addition, the system contains an impeller driven by the pull of an external weight and designed to dissipate mechanical energy. Before closing the box you pour 1 L of water at 20 ◦C and then add 100 g of ice at -8 ◦C in the beaker.
• A) Once the box is sealed, what happens inside the beaker? If you wait a few hours, what is the composition inside the beaker? Is there only water, only ice or still a mix of ice and water? If your answer includes the presence of ice then calculate how much ice remains. In any case, calculate the temperature of whatever is contained in the beaker.