White light is incident on a soap film (n = 1.31) in air. The reflected light looks bluish because the red light (lambda= 680 nm) is absent in the reflection. What is the minimum thickness of the soap film?

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.