physics

posted by .

100 lumen of light are incident on an interface which has 25% reflectance. At a point 3cm into the new medium, the amount of transmitted light is measured as 50 lumen. What is the absorptance of the material per cm?

  • physics -

    0.75 * exp(-k*L) = 50/100 = 0.5

    L = 3 cm
    The 0.75 is the fraction that penetrates the surface.
    Solve for k
    exp(-kL) = 0.667
    kL = 0.4055
    k = 0.135 cm^-1

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. 12 Biology! URGENT!

    Is this right: Place numbers beside the statement below to indicate the order of events occurring in the light reactions: 3 low energy electrons at PSI are re-energized by a photon of light 5 electrons energized at PSII jump to a higher …
  2. 12 Biology! URGENT!

    Is this right: Place numbers beside the statement below to indicate the order of events occurring in the light reactions: 3 low energy electrons at PSI are re-energized by a photon of light 5 electrons energized at PSII jump to a higher …
  3. biology

    this right: Place numbers beside the statement below to indicate the order of events occurring in the light reactions: 3 low energy electrons at PSI are re-energized by a photon of light 5 electrons energized at PSII jump to a higher …
  4. physiology

    Gastrin is a hormone secreted into the __________ by the ___________. Blood; stomach Lumen; stomach Lumen; pancreas Blood; small intestine
  5. Biology- GI Tract

    I have a question regarding the gastric wall. Do the epithelial cells of the mucosa secrete substances directly into the lumen or do they secrete into the gastric pits then then from there the substances go into the lumen?
  6. Biology - The Stomach

    When referring to the lumen of the stomach is that just the opening. As in where are the HCl is and where your food enters?
  7. physics

    The angle between the polarizer transmission axis and the plane of polarization of the incoming light is 30 +/- 2 deg. If the incident light intensity Io is 100 W/cm2 what would be the intensity I after the light is transmitted through …
  8. physics

    Linearly polarized light is incident on a piece of polarizing material. What is the ratio of the transmitted light intensity to the incident light intensity when the angle between the transmission axis and the incident electric field …
  9. Physics

    A ray of light is incident on a material with reflective indeed n=1.46. if the material has thickness w=2.6mm; how many times does the light take to pass through the material?
  10. calculus-snell's law

    Suppose A light ray starts at the point A = (0,a) in an uniform medium 1 where the speed of light is c1 and then passes through an uniform medium 2 where the speed of light is c2 reaching point B = (d, −b). The line separating the …

More Similar Questions