(note: not actually biology, it's just that there isn't an earth and space science) The amount of energy received by a surface depends on the angle of incidence of the incoming light. The angle of incidence is the angle that a ray of light makes with an imaginary perpendicular line (a normal) extending from the surface. In this activity, you will answers question based on this and other information.

Part A

When we talk about energy from light that a surface receives, we use the word irradiance (E). Irradiance measures the amount of energy per second (P) that arrives on a surface per unit area (A). As an equation, this idea can be expressed in this way: E = P/A.

As the angle of the light source moves from 0° to 45°, the illuminated area (A) increases. You can see this increase in the image. However, although the illuminated area increases, the energy per second (P) from the light is constant. What effect will an increase in the angle of light, and therefore illuminated area (A), have on irradiance (E)? (here is the image if needed.)