Final answer:
The question deals with the properties of polarizing filters in physics and how they affect the intensity and polarization of light. Example calculations illustrate determining the angle required to reduce light intensity and how polarizing filters influence the heating rate of water when sunlight passes through them.
Step-by-step explanation:
The question pertains to the concept of polarizing filters in physics, particularly in the context of their effect on the intensity and polarization of light.
The axis of a polarizing filter is the direction along which the filter passes the electric field of an electromagnetic wave. When two polarizing filters are placed one after the other, the intensity of the light passing through them is dependent on the angle between their axes.
If the axes are parallel (a), all polarized light is transmitted. As the angle increases (b), the transmitted light intensity decreases, and it becomes completely blocked when the filters are perpendicular (c). Example 27.8 illustrates the calculation of intensity reduction, which applies the Malus's Law stating that the transmitted light intensity through a polarizer is proportional to the cosine squared of the angle between the light's initial polarization direction and the axis of the filter. In the given example, to achieve a 90.0% reduction in intensity, an angle can be determined using this law.
In a practical application, when sunlight passes through two polarizing filters at an angle of 20.0°, as described in question 89, the rate of heating water can be calculated considering the intensity reduction due to polarization and the absorption characteristics described for the polarizers and water, respectively.
The polarizing filters themselves can also increase in temperature due to absorption of some of the light energy they do not transmit.
Understanding polarizing filters is important for a variety of applications, including photography, glare reduction, and scientific instrumentation like confocal microscopes that can use polarized light for enhanced imaging.