0.75 ft
Explanation:
This situation is due to Refraction, a phenomenon in which a wave (the light in this case) bends or changes its direction when passing through a medium with an index of refraction different from the other medium. In this context, the index of refraction is a number that describes how fast light propagates through a medium or material.
In addition, we have the following equation that states a relationship between the apparent depth and the actual depth :
Where:
is the air's index of refraction
is the actual depth of the quarters
Now. when is smaller than the apparent depth is smaller than the actual depth. And, when is greater than the apparent depth is greater than the actual depth.
Let's prove it:
Finally we find the aparent depth of the quarters, which is smaller than the actual depth: