The ball is in the pool (point A) to the edge of which is an observer (point B). A minimum distance ball from the edge of the pool is 36 m (point C), and an observer to that point has to walk along the edge of 42 m.
a) If the speed of walking along the edge of the pool of 1.5 m / s, and the swimming speed of 0.9 m / s, find a way to be an observer to move from point B to point A. came
b) How much (minimum) time would be needed for it, and how long it would take him when he went diagonally (from B to A)?
c) Get rid of the task using the laws of geometric optics.