Integrated Concepts

(a) On a day when the intensity of sunlight is $1 . \text{00} \text{kW} / \text{m}^{2}$, a circular lens 0.200 m in diameter focuses light onto water in a black aluminum beaker. Two polarizing sheets of plastic are placed in front of the lens with their axes at an angle of $\text{20} . 0º.$ Assuming the sunlight is unpolarized and the polarizers are $\text{100}\%$ efficient, what is the initial rate of heating of the water in $º\text{C} / \text{s}$, assuming it is $\text{80} . 0$ absorbed? The aluminum beaker has a mass of 30.0 grams and contains 250 grams of water. (b) Do the polarizing filters get hot? Explain.