Using a laptop screen to model point-source, line-source, and planar-source fields

摘要

The relationship between the intensity of a field and the 1 distance from the source of the field is central to several topics taught in introductory physics. For example, most introductory texts include a description of how the intensities of gravitational and electric fields follow an inverse-squared relationship between the intensities of the field and distance from an object with mass or charge. Many high school and college curricula include labs showing the inverse-squared relationship for the intensity of a field of a point source as a function of distance. These demonstrations are straightforward because point sources are readily available. For example, a small low-voltage bulb can serve as a point source for light.' Students extrapolate their results from these labs to other kinds of fields.