🔍 Key Concepts

• Free surface effect (FSE) causes an apparent reduction in GM because the center of gravity moves when liquid shifts. • Use the second moment of area of the free surface about the centerline: for a rectangular tank, ( I = \frac{L \times B^3}{12} ) when considering transverse stability. • Relate the moment of inertia of the free surface and the ship’s total displacement (684 tons) to find the reduction in GM.

💭 Think About

• How do you find the total weight of water in the fish hold from the given: tank dimensions, 2 ft depth, and "each foot of water weighs 26.5 tons"? • Once you know the tank’s moment of inertia (I) about the centerline, how is the GM reduction related to ( I ) and the vessel’s displacement ( \Delta )? • Are you using the correct tank dimension as breadth (B) for transverse stability, and keeping all units (feet and tons) consistent in your calculation?

✅ Before You Answer

• Compute the total tons of water in the hold correctly using the 2 ft depth and the given tons per foot of water. • Use the proper formula for rectangular free surface moment of inertia, making sure the breadth (B) is the dimension measured across the ship. • Before picking an answer, verify that your computed reduction in GM (in feet) is in the same order of magnitude as the answer choices (a few feet, not inches or tens of feet).