On a hot, dry day, a traveler wraps a metal flask of water in a wet cloth sleeve. Why does this help to lower the temperature of the water inside the flask?
The water in the sleeve evaporates, absorbing thermal energy from the flask.
The wet cloth acts as a perfect insulator preventing any thermal conduction.
The water in the sleeve is naturally colder than the flask's contents.
The wet cloth reflects all incoming infrared radiation.
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.