You watch two otters cross a river of width d with water flowing at vw. Otter 1 swims across the river perpendicularly to the shore (but ends up actually swimming diagonally from the reference frame of a person standing on the shore because the river flows in a direction perpendicular to the direction the otter swims). Otter 2 swims in a direction that takes her directly across the river, on a path that is actually perpendicular to the shore as seen from a person standing on the shore. Each otter swims at vo relative to the water and they take the paths described above. How much longer does the Otter 2 take to cross the river? To answer this, derive an expression for the ratio of the time taken by the Otter 2 to cross the river divided by the time taken by the Otter 1 to cross the river. Get the ratio in terms of vo and vw and select the correct answer.