(Solved): 3.1 A floating buoy with a camera at the top is designed for swimming competitions. The buoy is made ...

3.1 A floating buoy with a camera at the top is designed for swimming competitions. The buoy is made by attaching a 3 cm thick lead disc to a 2.5 m long wooden post as shown below. The diameters of the lead disk and wooden post are 60 cm and 30 cm respectively. The sides of the buoy not in contact with water are exposed to the atmosphere. Determine the length \( d \) that is expected to be visible above the water surface when the buoy is floating vertically as shown below