One of the effects of pollution is the gradual build-up of layers

of grime on surfaces.  You are

investigating how this affect the performance of solar cells.  After one month without rain, you find that a

layer of grime with thickness

Plank’s constant , the speed of light

and the proton charge

Calculate the fraction of light that penetrates to the

solar cell through the grime (the ratio of the light intensity with the grime layer

and the light intensity of a solar cell when

State your answer as a decimal fraction, rounding to two

decimal places if necessary.