Light Reflection: 2 Mirrors 10ft Apart - 98M Reflections/sec?

[crashoran]

If you placed two mirrors facing each other exactly 10 feet apart (assuming 100% of the light is reflected), I figure light would pass back and forth between the mirrors ~98,208,000 times in 1 second. Or would it be half of that because the distance for two reflections traveled would actually be 20 feet? This one is hurting my brain..

Apologies for the randomness of this question but it came to me last night and has been bugging me since.

 

[mathman]

98 mil 1 way, 49 mil 2 ways.

 

[map19]

Is this in a vacuum ?
Either way, the speed of light in the mirror glass is 0.66c, the speed of light in air is 0.9997c.
Recalculate !