17. In a rectangular container with a square base of side length 60 cm, there stands a rectangular iron rod with a height of 1 meter and a square base of side length 15 cm. At this moment, the water in the container is half a meter deep. Now, the iron rod is gently lifted 24 cm upwards, and the length of the wet part of the iron rod above the water is $\qquad$ cm.
answer: 25.6