The author's cat enjoys chasing chipmunks in the front yard. In this game, the cat sits at one edge of a yard that is w = 29 m across (see figure), watching as chipmunks move toward the center. The cat can run faster than a chipmunk, and when a chipmunk moves more than a certain distance L from the far end of the yard, the cat knows that it can catch the chipmunk before the chipmunk disappears into the nearby woods. If the cat's top speed is 7.0 m/s and a chipmunk's top speed is 4.2 m/s, find L. Assume the chipmunk and cat move along the same straight-line path.