The percent of light that will pass through a material is given by the formula lgP = -kd, where P is the percent of light passing through the material (in fractions), k is a constant that depends on the material, and d is the thickness of the material in centimeters. The constant k for a piece of tinted glass is 0.4. How thick (in centimeters) is a piece of this glass that allows 50% of the light incident to the glass to pass through it? Round to the nearest hundredth of a centimeter.

Question

a.  1.73
b.  0.75
c.  4.25
d.  9.78
e.  3.32

Answer 1

b.  0.75