When light strikes glass perpendicularly, about 5.5% is reflected at each surface. How much light is transmitted through a pane of window glass?
How much is absorbed?
At the first surface, one has .945 being transmitted, then, ignoring absorbtion, at the second surface, (.945)^2 of the original gets transmitted.
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To determine how much light is transmitted through a pane of window glass, we can use the concept of transmittance. Transmittance is the ratio of the transmitted light to the incident light, expressed as a percentage.
Given that when light strikes glass perpendicularly, about 5.5% is reflected at each surface, we can calculate the amount of light transmitted as follows:
1. Start with 100% as the initial incident light.
2. When the light strikes the first surface of the glass, 5.5% is reflected, leaving 94.5% transmitted.
3. When this transmitted light reaches the second surface of the glass, another 5.5% is reflected off that surface, resulting in 94.5% of the previously transmitted light being transmitted once again.
4. Multiply the transmittance percentages to find the overall transmittance. In this case, since both surfaces are the same, we multiply 94.5% by itself.
Transmittance = 94.5% * 94.5%
= 89.4025%
Therefore, approximately 89.4% of the incident light is transmitted through a pane of window glass when light strikes it perpendicularly.