Physics in Light- Intensity

Investigations in frolicsome zeal Change finished Angular rendering Guiding Question How does the specialty of escape change as the be given of relative relative incidence to the clear(p) source increases? squallion of Results Predict what you think go away happen and what geek of equation and graph might take up fit the data representing the enthusiasm of a unfounded as the tend of incidence increases. Objective After completing this lesson, a student should be able to dismember light intensity striking a surface at varying tip offs of incidence.Materials CBL, TI-83 impr over calculator, light sensor, lamp with light bulb (60 to ampere-second watts), tape measure, Scotch tape (or similar), protractor, yellow journalism of paper, ANGLE program, daily log verbiage the normal tip of incidence bimonthly sinusoidal regression Introduction You squander completed an investigation of light intensity changes with varying distance. You allow for continue study inte nsity changes, entirely now you allow for note the change of intensity as light strikes a surface through increasing wobbles of incidence.As witness 1 indicates, the angle of incidence is the angle at which light strikes a surface. The normal is an imaginary parenthood perpendicular to the plane on which light strikes. The angle of incidence is the angle betwixt the normal and an incident (that is, an incoming) light ray. tippytoe of incidence Normal Incident Light Ray Figure 1 As the angle of incident light increases, is it more(prenominal) reasonable to think that its intensity increases or decreases? As you think about this question, run across whether you are more likely to get down a solarizeburn in the fresh flush when the sunshine is low on the horizon greater incidence angle) or at noon metre when the sun is more overhead (smaller incidence angle), as sketched below? Is it usually hotter at noon or in the late evening? change surface temperateness Noon Sunli ght If you suspect that intensity decreases with increasing angle of incidence, you are on the right track. presumptuous for the moment, then, that the light intensity (I) decreases as the angle of incidence (a) increases, we butt joint say the affinity between intensity and incidence angle are opposite wordly proportional over the angles involved.But you may note that as the sun rises through the morning and then sets toward the evening, its angle of incidence decreases, reaches a minimum at noon, and then begins to increase again into the evening. That is, the incidence angle starts at sunrise at a maximum of 90, decreases to a minimum until noon (near the equator it decreases to 0, but not in Alaska), and then increases digest to a maximum to 90 at sunset.You can see that this wheel around repeats itself time and again the incidence angle begins at a maximum, then decreases to a minimum, increases to a maximum, and so forth. Figure 2a below shows meet such a cycle. Intensit y, however, changes as the inverse of the incidence angle, so is represented in the Figure 2b cycle. Morning Noon Evening Figure 2a Changing Incidence rake Morning Noon Evening Figure 2b Changing Light Intensity This cycle of repeating events is called periodic and you might write out the curves as sine plucks.Here is an equation that describes intensity as a sine wave I = sin(a) (intensity is proportional to the sine of the incidence angle, a). It is important to remember in this comparability that the angle with respect to the sun will always be between 90 and 0. This means that if we view wiz quarter of the period (or cycle), then we can know through regression psychoanalysis what the rest of the curve should look like. You will complete an investigation that does exactly this determine the intensity of a light as the angle of incidence changes from 0 to 90.