A 15-cm-deep opaque container is empty except for a single coin resting on its bottom surface. When looking into the container at a viewing angle of 50o relative to the vertical side of the container, you see nothing on the bottom. When the container is filled with water, you see the coin (from the same viewing angle) on the bottom of, and just beyond, the side of the container. How far is the coin from the side of the container?