We have a rectangular container with a square base of 60 centimeters. Inside, there's an iron block with a square base of 15 centimeters and height of 1 meter. The water level is currently 50 centimeters deep.
When we lift the iron block up by 24 centimeters, the water level drops because less volume is displaced. The wet part on the iron block shows where the water used to reach. We can calculate this wet length is 26 centimeters.
Let's calculate the volume changes step by step. The container base area is 60 times 60 equals 3600 square centimeters. The iron block base area is 15 times 15 equals 225 square centimeters. When lifted 24 centimeters, the displaced volume decreases by 225 times 24 equals 5400 cubic centimeters. This causes the water level to drop by 5400 divided by 3600 equals 1.5 centimeters, from 50 to 48.5 centimeters.
Now let's find the wet length on the iron block. The original water level was 50 centimeters. After lifting the block 24 centimeters up, the new water level is 48.5 centimeters. The wet length equals 50 minus the difference between 48.5 and 24, which is 50 minus 24.5, equals 26 centimeters. This is the length of the wet part on the iron block above the current water surface.