Serway & Jewett — The First Law of Thermodynamics: Problem 42.

Why is the following situation impossible? A group of campers arises at 8:30 a.m. and uses a solar cooker, which consists of a curved, reflecting surface that concentrates sunlight onto the object to be warmed (Fig. P19.42). During the day, the maximum solar intensity reaching the Earth’s surface at the cooker’s location is \(I = 600 \text{ W/m}^2\). The cooker faces the Sun and has a face diameter of \(d = 0.600 \text{ m}\). Assume a fraction \(f\) of \(40.0\%\) of the incident energy is transferred to \(1.50 \text{ L}\) of water in an open container, initially at \(20.0^\circ\text{C}\). The water comes to a boil, and the campers enjoy hot coffee for breakfast before hiking ten miles and returning by noon for lunch.