After a hard rain, you walk out into the parking lot and notice an oil sheen on top of a puddle of water. When viewed from directly above, the light reflected off the puddle is a bright red which you estimate to be a wavelength of 660 nm . The index of refraction of water is = 1.33 and the index of refraction of the oil is = 1.47.

1. What is the minimum thickness of the oil?

2.What is the longest wavelength of light that is transmitted into the water most effectively?